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The aim of the present study was to develop meat-based media with compositions similar to those of dry-fermented meat products and to evaluate their use in studying the growth of Aspergillus parasiticus and the kinetics of aflatoxin B1 (AFB1) production. In our previous experiments, we found that the strain A. parasiticus ŽMJ7 produced a high amount of AFB1. Cooked meat agar (CMA2) was used as a novel complex meat-based medium with four variations: CMA2G (CMA2 supplemented with 1% glucose), CMA2YE (CMA2 supplemented with 0.2% yeast extract), and CMA2GYE (CMA2 supplemented with 1% glucose and 0.2% yeast extract). Media were inoculated with an A. parasiticus spore suspension (105 spores/mL) and incubated at 25 °C for up to 15 days. The A. parasiticus lag phase lasted less than 1 day, irrespective of the growth medium, with the exception of control medium CMA1 (cooked meat agar) as an already known meat-based medium. The highest mean colony growth rate was observed on CMA2 and CMA2G. Reversed-phase UPLC–MS/MS analysis was performed to determine the AFB1 concentration in combination with solid phase extraction (SPE). The highest AFB1 concentration in meat-based media was detected in CMA2GYE after 15 days of incubation (13,502 ± 2367 ng/mL media). The results showed that for studying AFB1 production in dry-fermented meat products, novel suitable media such as CMA2-based media are required. This finding could represent a potential concern with regard to the production of dry-fermented meat products.

Uporaba fungicidov za zatiranje plesni, ki povzročajo kvar sadja in zelenjave, je vse bolj omejena. Vzroki so v dolgoletni preobsežni uporabi fitofarmacevtskih sredstev (FFS), razvoju novih sevov plesni, ki so prilagojeni ali celo odporni proti fungicidom ter v potencialno škodljivih vplivih ostankov pesticidov na zdravje ljudi. Zato so pomembne alternativne metode in ena od njih je uporaba modre LED-svetlobe, katere osnovni mehanizem temelji na fotodinamični inaktivaciji (PDI). Namen diplomskega dela je pojasniti fotodinamični vpliv modre LED-svetlobe in možnosti uporabe v praksi za zaviranje kvara sadja in zelenjave, ki ga povzročajo plesni. Pregled strokovne literature o uporabi modre LED-svetlobe na plodovih sadja in zelenjave med skladiščenjem je pokazal spodbudne rezultate. Pri obsevanju plesni na/v živilu z modro LED-svetlobo se tvorijo reaktivni kisikovi radikali (ROS), ki povzročijo poškodbe različnih celičnih sestavin kot so lipidi, proteini in nukleinske kisline, ki lahko vodijo do inhibicije rasti ali celo celične smrti in propada plesni. Modra LED-svetloba lahko vpliva tudi na samo kakovost živil, npr. sprememba barve plodov, povečanje vsebnosti nekaterih antioksidantov, kot so fenolne spojine, antocianini, upočasni se gnitje in staranje pridelkov ter poveča odpornost plodov proti boleznim, povzročenim s strani plesni. Uporaba modre LED-svetlobe predstavlja okolju prijaznejšo metodo v primerjavi z uporabo fungicidov in bi jo lahko komplementarno povezovali z drugimi metodami za zaščito in podaljšanje trajnosti sadja in zelenjave. Ker na učinkovitost modre LED- svetlobe vpliva veliko dejavnikov, bo za njeno uporabo v praksi potrebnih še veliko raziskav. The use of fungicides to control molds that cause spoilage of fruits and vegetables is increasingly limited. Mainly due to their excessive use in past, the development of new resistant mould strains and because of potentially harmful effects of pesticide residues to human health. Alternative methods are therefore increasingly important. One of them is irradiation of fruits and vegetables with blue LED light or photodynamic inactivation (PDI) with blue LED light. Researchers have demonstrated the antimicrobial effect of blue LED light mainly as antibacterial treatment and less frequently as antifungal treatment. The purpose of this work is to explain photodynamic effect of blue LED light irradiation and possibilities of its practical application as antifungal method used to prevent fruit and vegetable spoilage. The results have showed potential of blue LED light irradiation as it can inactivate mould by producing reactive oxygen species (ROS) that cause damage to different cellular components such as lipids, proteins and nucleic acids. These effects can lead to growth inhibition or even moulds destruction. Blue LED light might also affect quality of fruit and vegetables such as colour, increasing content of certain antioxidants, such as phenolic compounds, anthocyanins, slows rot and aging of fruits and vegetables and increase their resistance to mold-borne diseases. The use of blue LED light is a more environmentally friendly method compared to the use of fungicides and could be use as complementary strategies to protect fruit and vegetables from mould spoilage. As the efficiency of blue LED light is influenced by many factors, its application still requires many scientific research.

Jabolka zaradi svoje visoke vodne aktivnosti in vsebnosti sladkorjev omogočajo ugodne razmere za rast različnim plesnim. Najpogosteje se omenja plesni vrste Penicillium expansum, ki povzročajo modro plesen. Na jabolkih so te plesni sposobne sintetizirati sekundarne metabolite, med katerimi so tudi mikotoksini. V jabolkih in izdelkih iz jabolk je najbolj pogost patulin, ki je imunotoksičen in nevrotoksičen za ljudi, če se zaužije v visokih koncentracijah. Mejna vrednost za največjo dovoljeno vsebnost patulina v izdelkih iz jabolk je 50 µg/kg. Plesni najpogosteje vstopajo v notranjost sadja skozi poškodovano površino, kar se zgodi ob močnem dežju, napadu insektov ali neprevidnem rokovanju. Pogosto pride do okužb s plesnimi šele v skladiščnih prostorih. Najbolj priporočljivo je skladiščenje jabolk v hladilnicah in hladilnicah s kontrolirano atmosfero, kjer je nivo CO₂ in O₂ prilagojen tako, da je zorenje plodov čim bolj upočasnjeno. Kljub nizkim temperaturam in nizkim nivojem O₂ je rast plesni vrste P. expansum le upočasnjena in patulin še vedno lahko proizvajajo. Zato je patulin lahko prisoten v različnih izdelkih iz jabolk. Ker pa je patulin tudi termostabilen, je njegovo odstranjevanje zelo zahtevno. Učinkovito zniževanje vsebnosti patulina so pokazali nekateri procesi obdelave hrane, kot so čiščenje, pasterizacija in fermentacija. Poznamo pa tudi več fizikalnih, kemijskih in bioloških procesov odstranjevanja patulina iz izdelkov iz jabolk. Sem spadajo obdelava s toploto, svetloba UV, elektroporacija, uporaba visokih tlakov, ozona in mikroorganizmov. Nekateri postopki delujejo na principu adsorpcije patulina, drugi pa povzročajo njegovo degradacijo. Tudi s temi procesi obdelave odstranitev patulina iz končnih izdelkov ni možna v celoti, hkrati pa lahko pride tudi do nezaželenih sprememb v senzoričnih lastnostih in hranilni vrednosti živil. Apples provide favourable conditions for growth of various fungi, due to their high water activity and sugar content. Most commonly mentioned mould is Penicillium expansum, the cause of so called blue mould. On apples these fungi are able to synthesize secondary metabolites called mycotoxins. The most commonly present mycotoxin in apples and apple products is patulin, which is immunotoxic and neurotoxic to humans if ingested at high concentrations. The limit for maximum level of patulin in apple products is 50 µg/kg. Mould enters the fruit through the damaged surface, which occurs in case of heavy rain, insect attack or careless manipulation. However, mould infections often occur only in storage rooms. The most recommended way to storage apples is in refrigerated chambers and refrigerated chambers with controlled atmosphere, where the levels of CO₂ and O₂ are adjusted to slow down the ripening of the fruit. Despite low temperatures and low level of O₂ the growth of P. expansum is only slowed down and patulin can still be produced. Therefore, patulin can be present in various apple products. Since patulin is also thermostable, its removal is very difficult. Effective reduction of patulin has been demonstrated by certain food processing technologies, such as washing, pasteurization and fermentation. There are also several physical, chemical and biological processes of removing patulin from apple products. This includes heat treatment, light UV treatment, electroporation, use of high pressures, ozone and microorganisms. Some procedures function on patulin adsorption, while others provoke its degradation. Even with these processing technologies, the removal of patulin from apple products is not entirely possible, and there may also be negative changes in sensory quality and nutritional value of foods.

Plesni vrste Penicillium expansum povzročajo gnilobo številnih živil, med katerimi so te plesni najpogostejši kontaminanti jabolk. Ker plesni vrste P. expansum lahko tvorijo patulin, predstavljajo tudi tveganje za varnost živil. Glavni namen dela je bil določiti sposobnost njihove adhezije, saj večina strokovne literature opisuje bakterijsko adhezijo, medtem ko so raziskave adhezije plesni redke. V prvem delu smo metodo določanja adhezije z barvilom kristal vijolično (KV) optimizirali z izbiro gojišča (sladni agar in krompirjev agar) in starosti konidijev (7 in 10 dni) za pripravo inokuluma ter določitvijo valovne dolžine (570 nm in 584 nm) za kvantifikacijo adheriranih plesni. V drugem delu smo proučevali adhezijo plesni vrste P. expansum tako, da smo preverili vplive izbranih intrinzičnih in ekstrinzičnih dejavnikov. Rezultati so pokazali, da je za spremljanje adhezije boljše, ča uporabimo inokulum pripravljen iz 10 dni stare kulture, saj je bila adhezija tu veliko večja ter da gojišče, na katerem rastejo plesni za pripravo inokuluma, ne vpliva na adhezijo. Pri primerjavi rezultatov dobljenih z meritvami absorbanc sproščenega KV pri različnih valovnih dolžinah, razlik nismo zaznali. Med intrinzičnimi dejavniki smo ugotovili, da ima velik vpliv na adhezijo začetno število konidijev, saj je bila adhezija največja pri 108 K/ml (K: konidiji), ter čas adhezije plesni vrste P. expansum (adhezija po 20 urah je bila večja kot po 40 urah), medtem ko vrsta seva (tipski sev P. expansum ŽMJ 497, divji sev P. expansum ŽMJ 464) ni bistveno vplivala na adhezijo. Plesni vrste P. expansum dobro rastejo na številnih materialih, ki se uporabljajo tudi v živilski industriji, zato smo primerjali njihovo adhezijo na različnih površinah (polistiren, polipropilen, polietilen visoke gostote, polietilen tereftalat, steklo in nerjaveče jeklo). Največjo adhezijo smo določili na površini polistirena. Adhezijo plesni vrste P. expansum na vseh površinah smo opazovali tudi z vrstično elektronsko mikroskopijo in ugotovili, da so morfološke lastnosti povezane z vrsto površine. Zaključimo lahko, da je metoda barvanja s KV primerna kot preliminarna metoda določanja adhezije plesni in da se plesni vrste P. expansum dobro adherirajo na površino, vendar so potrebne nadaljnje raziskave. Strains of Penicillium expansum cause rotting of many foods, among which they are the most common contaminant of apples. As P. expansum can form patulin it is also a food safety risk. The main purpose was to determine P. expansum adhesion ability, since most scientific literature describes bacterial adhesion, while moulds adhesion is rare. In the first part, the method of determining adhesion with crystal violet dye (CV) was optimized by choosing medium (malt agar and potato agar) and age of conidia (7 and 10 days) for preparation of inoculum and determining the wavelength (570 nm and 584 nm) for adherence quantification. In the second part, we studied the adhesion of P. expansum by checking the influence of selected intrinsic and extrinsic factors. Results showed that for adhesion monitoring it is better to use an inoculum prepared from a 10-day-old culture, as the adhesion was much greater, and that the culture medium on which the moulds grow prior inoculum preparation, does not affect adhesion. When comparing the results obtained by measuring the absorbance of released CV at different wavelengths no differences were found. Among the intrinsic factors, we found out that initial number of conidia had a major influence since adhesion was highest at 108 K/ml (K: conidia), and adhesion time (adhesion after 20 h was greater than after 40 h), while strain (P. expansum ŽMJ 497 type strain, P. expansum ŽMJ 464 wild strain) did not affect adhesion. P. expansum strains grow well on many materials that are also used in food industry and we compared adhesion on different surfaces (polystyrene, polypropylene, high-density polyethylene, polyethylene terephthalate, glass and stainless steel). The maximum adhesion was determined on the polystyrene. Adhesion of P. expansum on surfaces was also observed by scanning electron microscopy and it was found that the morphological properties are related to the type of surface. We can conclude that the KV staining method is suitable as a preliminary method for determining mould adhesion and that P. expansum adhere well to the surface, but further research is needed.

V sklopu magistrskega dela smo želeli ugotoviti, kako praktičen pouk vpliva na spremembe v znanju in stališčih pri učencih sedmega razreda osnovne šole. Izvedli smo kvantitativno raziskavo, kjer smo uporabili kavzalno eksperimentalno metodo dela. Zasnovali smo vprašalnik s preizkusom znanja. Ta nam je služil kot orodje preverjanja znanja o plesnih in stališč učencev do njih. Učenci so anketni vprašalnik izpolnjevali dvakrat. Najprej pred začetkom eksperimentalnega dela in po eksperimentalnem delu (praktičen pouk). Z našo raziskavo smo ugotovili, da ni statistično pomembnih razlik v znanju med učenci pred poukom in po pouku, ravno tako se ne pojavljajo razlike glede na učno metodo. Učenci, ki so se učili na podlagi klasičnega pouka, ne kažejo sprememb v znanju v primerjavi z učenci, ki so se učili na podlagi praktičnega dela. Raziskava tudi ni pokazala razlik znanja glede na spol, deklice in dečki imajo primerljivo znanje o plesnih. Statistično pomembne razlike so se pojavile glede zanimanja (stališč) dečkov in deklic pri različnih učnih metodah. Dečki, s katerimi smo izvajali praktičen pouk, kažejo večje zanimanje za plesni. Zanima jih, kako plesni rastejo, radi bi proučevali plesni v naravi, zanima pa jih tudi, kaj bi zraslo na kruhu, zaprtem v kozarcu. In this thesis we wanted to find out how practical work affect the change in knowledge and attitudes towards molds in Seventh Grade students of Primary School. We have carried out a quantitative research in which we have used a cause/effect experimental method of work. We designed a questionnaire with a examination. With this questionnaire we have checked the knowledge and attitudes of the students towards molds. Students completed the survey questionnaire twice. First before the start of the experimental work and after the experimental work (practical work). With our research, we found that there are no statistically significant differences in knowledge between students before class and after class, and there are no differences according to the teaching method. Pupils who have learned through traditional lessons showed no changes in knowledge compared to pupils who have learned through practical work. The research also showed no differences in knowledge according to gender, girls and boys have comparable knowledge about molds. Statistically significant differences emerged regarding the interest (attitudes) of boys and girls in different teaching methods. The boys with whom we conducted practical classes show a greater interest in molds than girls. Boys are more interested in how molds grows, they would like to study molds in nature and they are also interested in what would grow on bread enclosed in a jar.

Uvod: Aflatoksini so eden izmed najbolj toksičnih sekundarnih metabolitov, ki jih producirajo različne vrste plesni, kot so Aspergillus flavus, Aspergillus parasiticus, Aspergillus nominus in druge. Kontaminacija lahko privede do resnih zdravstvenih zapletov pri ljudeh in živalih in vključuje hapatotoksičnost, teratogenost in imunotoksičnost. Namen diplomskega dela je analizirati strokovno in znanstveno literaturo, ki se nanaša na aflatoksine in njihovo povezavo s hepatokarcinomom. Ugotoviti želimo, kako vpliva njihova prisotnost na ljudi. Predstaviti želimo plesni, ki izločajo aflatoksine in možne načine ozaveščanja glede na njihove morebitne učinke na prebivalstvo. Metode dela: Uporabljena je deskriptivna metoda dela. Izveden je pregled znanstvene in strokovne literature. Izveden je bil pregled literature dostopne v obdobju od junija do avgusta 2021 preko portala Digitalne knjižnice Univerze v Ljubljani (DiKul). Rezultati: Večkratna izpostavljenost nizkim odmerkom aflatoksinov tekom življenja povzroča kronične bolezni, med katerimi je najpogostejši in najhujši pojav karcinom. Čeprav je prehranski vnos aflatoksinov klasično povezan z rakom jeter in hiperplazijo žolčevodov, so mnoge raziskave poročale tudi o malignih obolenjih drugih organov kot so ledvice, trebušna slinavka, mehur, kosti, viscera itd. Pravzaprav kronična izpostavljenost aflatoksinom povzroča vrsto hudih bolezni vključno z imunosupresijo, teratogenostjo, mutagenostjo, citotoksičnostjo in estrogenskimi učinki pri sesalcih. Za posameznike, ki že imajo razvite kronične bolezni ali pa so v stiku z dejavniki tveganja je posebej pomembna osveščenost o zdravstvenem problemu in situaciji. Najboljša pozitivna sprememba je lahko prilagoditev življenjskega sloga. Za preprečevanje in učinkovitejše obvladovanje kroničnih nenalezljivih bolezni bi bila potrebna preusmeritev zdravstvene dejavnosti na primarni ravni v promocijo zdravja in izobraževanje o varni hrani že od osnovne šole naprej. Razprava in zaključek: S pregledom literature smo potrdili, da izpostavljenost aflatoksinom povzroča hepatocelularni karcinom in druge vrste zdravstvenih zapletov. Začetna hipoteza o kancerogenem učinku je potrjena. Opredelili smo zdravstveno vzgojne strategije za zmanjševanje dejavnikov tveganja in predstavili tudi nekaj okvirnih podatkov o pričakovanih rezultatih ob implementaciji načrtov. Smiselno bi bilo nadaljevati z raziskavami na tem področju. Introduction: Aflatoxins are one of the most toxic secondary metabolites produced by various types of molds such as Aspergillus flavus, Aspergillus parasiticus, Aspergillus nominus and others. Contamination can lead to serious health complications for humans and animals, including hapatotoxicity, teratogenicity and immunotoxicity. Purpose: The purpose of this thesis is to analyze the professional and scientific literature related to aflatoxins, which can cause hepatocarcinoma. We want to find out how their presence affects people. We aim to describe molds that secrete aflatoxins and possible ways to raise awareness about their greater effects on the population. Methods of work: A descriptive method of work is used to review scientific in the professional literature. A review of the literature available in the period from June to August 2021 was carried out through the portal of the Digital Library of the University of Ljubljana (DiKul). Results: Repeated exposure to low-dose aflatoxins during life can cause chronic diseases. Among them is cancer. Although dietary intake of aflatoxins is classically associated with liver cancer and bile duct hyperplasia, many studies have also reported malignancies of other organs such as the kidneys, pancreas, bladder, bones, viscera, and so on. Chronic exposure to aflatoxins causes immunosuppression, teratogenicity, mutagenicity, cytotoxicity, and estrogenic effects in mammals. Awareness of the health problem in the situation is especially important for individuals who already have various chronic diseases or are in contact with risk factors. The best positive change can be a healthy lifestyle. The prevention and effective management of chronic diseases would require a reorientation of health activities at the primary level in health promotion. Discussion and Conclusion: We have confirmed that exposure to aflatoxins acts on hepatocellular carcinoma and other types of health complications. The initial hypothesis of a carcinogenic effect was confirmed. We have identified health strategies to reduce risk factors and also presented some indicative data on expected results in implementation planning. It would make sense to continue research in this area.

V diplomskem delu smo proučevali primerljivost alternativne metode za določanje kvasovk in plesni (SimPlate Y&M CI) s klasično metodo za kvantifikacijo kvasovk in plesni na gojišču DRBC (gojišče z barvilom dikloran rdeče in bengal ter kloramfenikolom). Alternativna metoda, ki je od klasične hitrejša ter enostavnejša, bi lahko na področju živilstva zelo pripomogla k pravočasnemu odkrivanju kvarljivcev živil. Mikrobiološko preiskavo smo izvedli z naravno kontaminiranim vzorcem zgornjesavinjskega želodca ter umetno kontaminiranim vzorcem zgornjesavinjskega želodca, ki smo mu dodali kvasovke vrste Saccharomyces cerevisiae v koncentraciji 108 CFU/ml. Po podaljšani inkubaciji (8 dni) alternativna in klasična metoda kvantifikacije kvasovk in plesni v živilu nista dali primerljivih rezultatov. Možen in najbolj verjeten vzrok so bile spremembe dehidriranega gojišča SimPlate. Nadaljnje raziskave z metodo SimPlate Y&M CI za določanje kvasovk in plesni v živilu bi vključevale izvedbo mikrobioloških preiskav z več različnimi živili (npr. surova živila, izdelki tekoča poltrdna in trdna živila) in z različnimi mikroorganizmi (npr. različne vrste kvasovk, plesni, mešane kulture, ki bi bile naravno prisotne in dodane v majhnem ter velikem številu) in več ponovitvami. The aim of thesis was to determine the comparability of an alternative method for the quantification of yeasts and molds (SimPlate Y&M CI) with the traditional method for quantification of yeasts and molds on DRBC agar (dichloran rose-bengal chloramphenicol agar). SimPlate Y&M CI as an alternative method is faster and simpler than the traditional method and therefore could contribute significantly to faster detection of spoilage yeasts and molds in food. Microbiological tests were performed on a naturally contaminated sample of Zgornjesavinjski želodec and an artificially contaminated sample of Zgornjesavinjski želodec to which Saccharomyces cerevisiae was added at a concentration of 108 CFU/ml. After a prolonged incubation of 7 days, the alternative and traditional methods did not give comparable results. The possible and most probable cause for the results obtained is changes in the dehydrated SimPlate medium. Further investigation of the SimPlate Y&M CI method for the quantification of yeasts and molds in foods should include microbiological tests on several different foods (e.g. raw foods, food products, liquid, semi-solid and solid foods) and with different microorganisms (different yeasts, different molds or mixed cultures naturally present and added at lower and higher concentrations) and several replicates.

Cilj diplomske naloge je bil ugotoviti, kako površinske poškodbe vplivajo na dinamiko navlaževanja lesenih okenskih profilov. Za raziskavo smo pripravili vzorce različnih lesenih okenskih profilov s površinskimi razami in poškodbami toče ter jih v časovnem obdobju dveh mesecev izpostavili tedenskemu ciklu, sestavljenem iz 4 faz (izpostavitev visoki zračni vlažnosti, sušenje, simulacija dežja, sušenje). Po vsaki fazi cikla smo vzorcem izmerili maso in vlažnost. Analizirali smo tudi barvne spremembe površine. Cilj naloge je bil tudi ugotoviti, kako določene površinske poškodbe vplivajo na razvoj gliv modrivk in plesni. Drugi skupini enako pripravljenih vzorcev, izpostavljenih v klimi z visoko relativno zračno vlažnostjo, smo vsak teden izmerili maso ter opazovali razvoj plesni in gliv modrivk na površini. Ugotovili smo, da površinske poškodbe ne vplivajo na spremembo barve. Kontrolni vzorci brez površinskega premaza so imeli največje barvne spremembe. Hipoteza, da bodo vzorci poškodovanih lesenih okenskih profilov imeli višjo vlažnost, kot referenčni nepoškodovani vzorci, je bila pravilna, saj so pri vsaki izpostavitvi visoki vlagi vzorci s poškodbami dosegali višje vrednosti. Poškodbe niso vplivale na končno vlažnost po sušenju. Poškodbe zaradi toče so najbolj vplivale na dinamiko navlaževanja. Druga hipoteza, da se bodo pod poškodovanim zaščitnim filmom prej pojavile glive modrivke kot pod nepoškodovanim zaščitnim filmom, je bila pravilna, saj so se hife najprej pojavile na poškodovanih območjih. The aim of the diploma thesis was to determine how certain surface damages affect the moisture dynamics of wooden window profiles. For the research, we prepared samples of various wooden window profiles with surface scratches and hail damage and exposed them to a weekly cycle consisting of 4 phases (exposure to high humidity, drying, rain simulation, drying) over a period of two months. After each phase of the cycle, the samples were measured for mass and moisture content. We also analysed the colour changes of the surface. The aim of the thesis was also to determine how certain surface damages affect the development of mould and staining-fungi. We measured the mass of another group of equally prepared samples every week that were exposed to a climate with high relative humidity and observed the development of mould and staining-fungi on the surface. We found that surface damage did not affect the colour change. Control samples without surface coating had the largest colour changes. The hypothesis that the samples of damaged wooden window profiles will have a higher wood moisture content than the reference undamaged samples was correct, as with each exposure to high humidity, the damaged samples reached higher values. The damage did not affect the final moisture content after drying. Hail damage had the greatest impact on moisture dynamics. The second hypothesis that staining-fungi would appear under the damaged protective film sooner than under the undamaged protective film was correct, as hyphae first appeared in the damaged areas.

This study aimed to test different chemical agents to obtain microbiologically safe industrial hemp seeds that could be used for further food processing (with the reduced total number of microorganisms, total number of moulds and yeasts, and total number of Enterobacteriaceae). In order to obtain seeds applicable for food consumption, optimal storage temperature conditions (room temperature, refrigerator, freezer), method of seed packaging (vacuum/without vacuum), and the application of various chemical treatments (ethanol, sodium hydrogen carbonate, sodium hypochlorite) were tested on the certified industrial hemp seeds, produced in two consecutive years. Optimal storage conditions differed for different microorganisms, and the most optimal storage was at room temperature, for seeds produced in 2018, in the treatment to reduce the total number of Enterobacteriaceae and the total number of microorganisms. When storing seeds from 2018 in order to reduce the number of yeasts and moulds, a slightly lower number was spotted when seeds were stored in a vacuum-sealed bag, at the refrigerator/freezer temperature. For hemp seeds produced in 2019, the most optimal storage conditions were at the refrigerator (for reduction of the total number of Enterobacteriaceae) and freezer temperature (for reduction of the total number of microorganisms). For the reduction of the total number of moulds and yeasts, optimal conditions were at room temperature. Ethanol (75%, v/v) was the most effective disinfectant among the tested chemicals regardless of the initial number of microorganisms, with log reduction of 3.2 (for the total number of Enterobacteriaceae), 2.9 log (for the total number of microorganisms), and total reduction of the total number of yeasts and moulds after 10 minutes, for the seeds harvested in 2019, which were far more contaminated than the seeds harvested in 2018. Considering the price of the disinfection method with ethanol, sodium hypochlorite may be a better solution for the reduction of the number of microbiota on the seeds. Cilj ovog istraživanja bio je ispitivanje različitih hemijskih sredstava za dobijanje mikrobiološki bezbednog semena industrijske konoplje, koje bi se moglo koristiti za dalju preradu u hranu (sa smanjenim ukupnim brojem mikroorganizama, ukupnim brojem kvasaca i plesni, i ukupnim brojem enterobakterija). Da bi se dobilo seme primenljivo za ishranu, optimalni temperaturni uslovi skladištenja (sobna temperatura, frižider, zamrzivač), način pakovanja semena (vakuum/bez vakuuma) i primena različitih hemijskih tretmana (etanol, natrijum hidrogen karbonat, natrijum hipohlorit) su testirani na sertifikovanom semenu industrijske konoplje, proizvedenom u dve uzastopne godine. Optimalni uslovi skladištenja su se razlikovali za različite mikroorganizme, a najoptimalnije skladištenje je bilo na sobnoj temperaturi, za seme iz 2018. godine, a u cilju smanjenja broja enterobakterija i ukupnog broja mikroorganizama. Pri skladištenju semena iz 2018. godine u cilju smanjenja broja plesni i kvasaca primećen je nešto manji broj datih mikroorganizama kada je seme čuvano u vakuumski zatvorenoj vrećici, na temperaturi frižidera/zamrzivača. Za seme konoplje iz 2019. godine najoptimalniji uslovi skladištenja su bili na temperaturi frižidera (za redukciju broja enterobakterija) i u zamrzivaču (za redukciju ukupnog broja mikroorganizama). Za smanjenje ukupnog broja plesni i kvasaca, optimalni uslovi su bili na sobnoj temperaturi. Etanol (75%, v/v) je bio najefikasnije sredstvo za dezinfekciju među ispitivanim hemijskim sredstvima, bez obzira na početni broj mikroorganizama, sa log smanjenjem od 3,2 (za ukupan broj enterobakterija), 2,9 log (za ukupan broj mikroorganizama) i ukupnim smanjenjem broja kvasaca i plesni nakon 10 minuta delovanja, za seme proizvedeno 2019. godine, koje je bilo mnogo više kontaminirano u odnosu na seme iz 2018. godine. Uzimajući u obzir cenu metoda dezinfekcije etanolom, natrijum hipohlorit može biti bolje rešenje za smanjenje broja mikrobiota na semenu.

Predmet doktorske disertacije obuhvata ispitivanje uticaja etarskih ulja lekovitih i začinskih biljaka (mente, kima i ruzmarina) na rast plesni izolovanih iz različitih žitarica i njihovih mlinskih proizvoda, kao i na mikrobiološku ispravnost i održivost testanih kora sa dodatkom 10% integralnog pšeničnog, heljdinog kukuruznog brašna.Utvrđen je stepen kontaminacije plesnima pšenice, heljde i kukuruza, pšeničnog brašna tip 500, pšeničnog integralnog brašna, heljdinog integralnog brašna i kukuruznog integralnog brašna koja su korišćena za proizvodnju testanih kora. Iz uzoraka pšenice, kukuruza i heljde najčešće su izolovane plesni iz roda Fusarium (100%), zatim iz roda Alternaria, Cladosporium i Penicillium (67%) i roda Aspergillus, Rhizopus i Scopulariopsis (33%). Najveću rasprostranjenost u brašnima žitarica imao je rod Penicillium (100%), zatim Aspergillus, Cladosporium i Fusarium (75%). Najzastupljenija vrsta bila je P. aurantiogriseum (100%), zatim C. cladosporioides sa zastupljenošću od 75%.Glavne komponente etarskog ulja mente bile su mentol, menton i mentilacetat, kima karvon i limonen, a ruzmarina 1,8-cineol, kamfor, α-pinen i β-pinen. Etarska ulja mente, kima i ruzmarina pokazala su antifungalnu aktivnost prema svim testiranim izolatima plesni (Alternaria alternata, Aspergillus flavus, A. fumigatus, A. niger, A. versicolor, Cladosporium cladosporioides, Fusarium proliferatum, F. sporotrichioides, Penicillium aurantiogriseum, P. expansum i P. oxalicum). Vrednosti MIC i MFC ukazale su da su etarska ulja mente i kima bila mnogo efikasnija u inhibiciji rasta plesni u odnosu na etarsko ulje ruzmarina.Polazeći od osnovnog sirovinskog sastava testanih kora, deo pšeničnog brašna tip 500 zamenjen je integralnim pšeničnim heljdinim integralnim i kukuruznim brašnom u količini od 10%. Količine etarskih ulja za ispitivanje antifungalne zaštite testanih kora utvrđene su na osnovu dobijenih rezultata antifungalne aktivnosti etarskih ulja na odabrane vrste plesni za vrednosti 0,5 MIC, 1 MIC i 1,5 MIC. Testane kore su skladištene i ispitivane prema sledećoj dinamici: 0, 5, 7, 14 i 21 dan skladištenja na temperaturi od 8°C. Ispitivanja testanih kora su obuhvatila mikološka, fizičko-hemijska i senzorska ispitivanja. Mikopopulacija uzoraka testanih kora od pšenišnog brašna tip 500 i testanih kora sa dodatkom pšeničnog integralnog, heljdinog integralnog i kukuruznog integralnog brašna, bez dodatka etarskog ulja, svrstana je u 5 rodova (Aspergillus, Cladosporium, Fusarium, Penicillium i Rhizopus) i 9 vrsta. Najčešće izolovani iz uzoraka testanih kora su rodovi Cladosporium i Penicillium koji su bili utvrđeni u svim uzorcima sa učestalošću od 100%. Najzastupljenije vrste sa 100% učestalosti pojavljivanja bile su P. aurantiogriseum i C. cladosporioides. Za sve uzorke testanih kora utvrđeno je da je etarsko ulje kima u koncentracijama od 0,17% i 0,255% nakon 14 dana skladištenja ispoljilo veoma dobra inhibitorna svojstva, što je rezultiralo smanjenjem ukupnog broja plesni i jednom izolovanom vrste P. aurantiogriseum. Rezultati deskriptivne metode senzorske ocene testanih kora pokazali su najveće razlike uočene u pogledu intenziteta i ujednačenosti boje. Uzorci testanih kora se zanačajno se razlikuju po aromi koja je najintenzivnija kod testanih kore sa dodatkom 10% pšeničnog integralnog brašna. Rezultati diskriminatornog testa potvrdili da postoje značajne razlike u intenzitetu mirisa testanih kora pri višim koncentracijama dodatog etarskog ulja. Najvećim razlikama je doprineo dodatak etarskog ulja ruzmarina, a najmanje kima. Minimalne prome mirisa utvrđene su kod testanih kora proizvedenih sa dodatkom 10% pšeničnog integralnog brašna Fizičko-hemijska svojstva (aw vrednost, količina vode, stepen kiselosti) uzoraka testanih kora su se menjala tokom skladištenja.Na osnovu ciljeva doktorske disertacije, izvršenih ispitivanja i postignutih rezultata može se zaključiti da su ispitivana etarska ulja, kao i odabrane koncentracije doprineli produženju održivosti pekarskog proizvoda-testanih kora. Primenom etarskog ulja kima u koncentracijama od 0,17% i 0,255% moguće je skladištiti testane kore u periodu do 14 dana pri temperaturi od 8°C, pri čemu su senzorski najprihvatljivije testane kore sa 10% pšeničnog integralnog brašna., The subject of the doctoral thesis contains research of the influence of medicinal and spice plants essential oils to the growth of molds isolated from various cereals and flours, the development of phyllo dough with the addition of examining cereal flour and essential oils, also as microbiological research of dough stability.Degree of mold contamination of wheat, buckwheat and corn, wheat flour T-500, whole grain wheat flour, whole grain buckwheat flour and whole grain corn flour, which are used for phyllo dough production was determined. From the samples of wheat, corn and buckwheat the most frequent isolated molds were from the genus Fusarium (100%), followed by Alternaria, Cladosporium and Penicillium (67%) and Aspergillus, Rhizopus andScopulariopsis (33%). Penicillium (100%), Aspergillus, Cladosporium and Fusarium (75%), have shown the largest distribution in cereal flours. The most frequent species were P. aurantiogriseum (100%), and C. cladosporioides with the frequency of 75%.The major components of mint essential oils were mint, menthone and menthyl acetate. The major components of caraway essential oils were carvone and limonene. The major components of rosemary essential oils were 1,8-cineole, camphor, α-pinene and β-pinene. Essential oil of mint, caraway and rosemary have shown antifungal activity towards all tested isolates (Alternaria alternata, Aspergillus flavus, A. fumigatus, A. niger, A. versicolor, Cladosporium cladosporioides, Fusarium proliferatum, F. sporotrichioides,Penicillium aurantiogriseum, P. expansum, and P. oxalicum). MIC and MFC values have indicated that essential mint and caraway oils were much efficient in mold growth inhibition in comparison to rosemary essential oil.Starting with the basic ingredients content of phyllo dough, the part of wheat flour T-500 was replaced with whole grain wheat flour, whole grain buckwheat flour, and whole grain corn flour in quantity of 10%. Essential oil quantities for research of phyllo dough antifungal protection were determined on the basis of essential oil antifungal activities results of selected species for the values 0,5 MIC, 1 MIC and 1,5 MIC. Phyllo doughs were stored and researched by the following dynamics: 0, 5, 7, 14 and 21 day of storing at 8°C. Researches of phyllo dough were contained: mycological researches, physico-chemical and sensory researches. Mycopopulation of the phyllo dough samples with wheat flour T-500 and phyllo dough with the addition of whole grain wheat flour, whole grain buckwheat flour and whole grain corn flour, without the addition of essential oil, was classified into 5 genera (Aspergillus, Cladosporium, Fusarium, Penicillium and Rhizopus) and 9 species. Among phyllo dough samples, the most frequent isolated generaCladosporium and Penicillium were detected in all samples with the frequency of 100%. Most represented species with the appearance frequency of 100% were P. aurantiogriseum and C. Cladosporioides. For the all samples of phyllo dough was determined that caraway essential oil concentrations of 0,17% and 0,255% after 14 days of storing have shown very good inhibitory abilities, which resulted with decrease of the total number of molds and one isolated species P. aurantiogriseum. Results of descriptive method of phyllo dough sensorial analyses have shown the biggest differences, spotted in the intensity and color uniformity of phyllo dough. Samples of phyllo dough were significantly different in cereal aroma, whereas, the phyllo dough with the addition of 10% whole grain wheat was with the most intense aroma. Results of discriminatory tests have shown that the differences in the aroma intensity were significant in higher concentration of added essential oil. The addition of rosemary essential oil has affected the highest differences, while the caraway essential oil has affected the lowest differences. The lowest aroma intensity variations were determined in phyllo dough with the addition of 10% whole grain wheat flour. Physico-chemical abilities (aw value, moisture content, acid number) of the phyllo dough samples have changed during the storing period.On the basis of doctoral thesis aims, conducted research and obtained results, it could be concluded that examined essential oils, also as selected concentrations, were contributed to the shelf life prolongation of the bakery products – phyllo dough pastry. By application of caraway essential oil in concentrations of 0,17% and 0,255% it's possible to store phyllo dough pastry up to 14 days at the temperature of 8°C, whereas, by following sensory characteristics the most acceptable phyllo dough pastry were with the addition of 10% whole grain wheat flour.

Namen magistrskega dela je bil ugotoviti vpliv tretiranja breskev s toplo vodo na zaviranje rasti plesni vrste Penicillium expansum. Breskve (Prunus persica) sorte Redhaven smo najprej razkužili z NaOCl (2 %, 2 minuti), nato smo jih razdelili v 4 skupine, ki smo jih različno tretirali: i) s toplo vodo (60 °C, 2 minuti) (TV), ii) s toplo vodo in inokulirali plesni vrste P. expansum (TVP), iii) brez tople vode in inokulirali plesni vrste P. expansum (P), iv) brez tople vode in brez dodatka plesni (B). Vse breskve smo 5 dni skladiščili pri 20 °C. Preiskave smo izvedli ločeno na kožici rdeče in kožici rumeno obarvanega dela plodu in so vključevale: antioksidativni potencial (AOP), skupne fenole, aktivnost fenilalanin amonijak liaze (PAL), barvo površine plodov, površino poškodbe plodu zaradi plesni vrste P. expansum, in mejni kot na površini plodov. Vrednosti AOP so se povečale po 5 dnevnem skladiščenju pri breskvah TVP na rdeče in rumeno obarvanem delu breskev, in enako smo na breskvah TVP določili manjšo površino poškodbe zaradi plesni vrste P. expansum. Analogno je topla voda vplivala na spremembo površine rumenih delov breskev, ker je le-ta postala hidrofobna. Blaga toplotna obdelava breskev je vplivala na počasnejšo rast plesni vrste P. expansum na plodovih, kar je bilo v korelaciji s povečanjem antioksidativnega potenciala breskev v skupini TVP na rdeče in rumeno obarvanih delih. Obdelava s toplo vodo je doprinesla k zmanjšani aktivnosti plesni vrste P. expansum. The aim of this MSc thesis was to determine the impact of hot water dipping of peach fruit on growth inhibition of Penicillium expansum. Peach fruits cv. Redhaven were first disinfected in NaOCl (2% for 2 minutes) and then divided in four groups, which were: i) peach fruits treated in hot water (60 °C for 2 minutes) and allowed to dry on air (TV), ii) peach fruits treated with hot water inoculated with P. expansum (TVP), iii) peach fruits without hot water treatment and with P. expansum inoculation (P), iv) peach fruits without HWD treatment and without P. expansum inoculation (B). Peach fruit was stored at 20 °C for 5 days. Analyses were carried out in skin of red and yellow fruit skin and included: antioxidative potential (AOP), total phenols, activity of phenylalanine ammonia lyase (PAL), fruit surface colour, surface of P. expansum lesion and fruit surface contact angle. Higher AOP was found in red and yellow coloured skin in TVP peaches, and also smaller surface of P. expansum lession was found on this test group. In analogy to the previous, hot water had impact on the surface of the yellow coloured skin, as it has become more hidrofobic. HWD had impact on slower growth of P. expansum on peach fruit, which is correlated to higher AOP for red and yellow coloured skin in TVP test group. Treatment with hot water caused reduced activity of P. expansum.

Plesni rodu Aspergillus so prisotne povsod v okolju. Posamezniki običajno vdihnejo stotine konidijev na dan. Pri večini ljudi so obrambni sistemi sposobni zlahka odstraniti glive iz pljuč. Če imunsko oslabljeni ljudje vdihnejo konidije vrste Aspergillus fumigatus, lahko pride do invazivne aspergiloze. Zdravila, ki se najpogosteje uporabljajo za zdravljenje aspergiloze, so azoli. Zaradi pogoste rabe azolov v kmetijstvu prihaja v naravi do večjega števila odpornih izolatov A. fumigatus proti azolom. Cilj magistrske naloge je bil opredeliti prevalenco proti azolom odpornih izolatov A. fumigatus v vzorcih zemlje iz področja ekoloških kmetij in hortikulturnih nasadov. Seve A. fumigatus sensu lato smo osamili na osnovnih mikoloških gojiščih. Občutljivost proti azolom smo opredelili s presejalnim testom VIPcheckTM. Odpornim sevom smo skušali molekularno dokazati prisotnost najpogosteje opisane mutacije TR34/L98H. Testirali smo 153 različnih vzorcev, od tega smo A. fumigatus izolirali iz 103 vzorcev. Od teh 103 vzorcev, smo s presejalno metodo VIPcheckTM našli tri izolate odporne proti azolom (dva proti itrakonazolu in enega proti vorikonazolu). Vsi trije izolati so izvirali iz Mozirskega gaja. Vsem trem domnevno odpornim izolatom smo testirali občutljivost z gradient difuzijsko metodo. Iz podatkov minimalnih inhibitornih koncentracij smo ugotovili, da je samo en od treh izolatov sodil med odporne, saj je izkazal visoke vrednosti zlasti za itrakonazol in tudi za posakonazol. Vse tri izolate smo opredelili tudi z molekularno metodo (PCR v realnem času). Izolat, ki je z gradient difuzijsko metodo izkazoval odpornost proti azolom nosi mutacijo na cyp51A genu, TR34/L98H. Molds of genus Aspergillus is ubiquitous in the environment. Individuals typically inhale hundreds of conidia per day. For the vast majority of people, their defense systems are able to easily remove fungi from lungs. If immunocompromised people inhale the conidia of Aspergillus fumigatus, invasive aspergillosis may occur. The most commonly used drugs to treat aspergillosis are azoles. Owing to the frequent use of azoles in agriculture, more resistant A. fumigatus isolates against azoles occur in nature. The aim of my master's thesis is to determine the prevalence of azole-resistant A. fumigatus isolates in soil samples from organic farms and horticultural plantations. A. fumigatus sensu lato strains were isolated on basic mycological media. Sensitivity to azoles was determined by VIPcheckTM screening test. We were sought to molecularly demonstrate the presence of the TR34/L98H mutation on resistant strains. 153 different samples were tested, of which A. fumigatus was isolated from 103 samples. Of this 103 samples, we found 3 resistant isolates using the VIPcheckTM method (two against itraconazole and one against voriconazole). All three isolates came from horticultural plantation Mozirski gaj. All three supposedly resistant isolates were tested for sensitivity using a gradient diffusion method to obtain data on the minimum inhibitory concentration. With this method, only one sample proved to be resistant to itraconazole and posaconazole. We tested all three samples with a molecular methode (a real time PCR). An isolate, that showed azole resistance by a gradient diffusion method carries a mutation in the cyp51A gene, TR34/L98H.

Aflatoksin B1 (AFB1) je strupen sekundarni presnovek nekaterih sevov plesni rodu Aspergillus, ki zaradi mnogih škodljivih lastnosti predstavlja resen problem za zdravje ljudi. Poleg tega povzroča velike ekonomske izgube v kmetijstvu in živilstvu. AFB1 najdemo v številnih živilih kot so koruza, riž, drevesni oreščki, arašidi, in suho sadje. Lahko se tvori pred ali med skladiščenjem. Učinkovit način nadzora AFB1 je ustrezen način pakiranja živila. Študije so pokazale, da so nekateri polimerni embalažni materiali dobra bariera za pline in vlago, ki sta glavna dejavnika, ki vplivata na rast plesni. Med te embalažne materiale štejemo polietilen-laminiran aluminij, etilen vinil alkohol, polipropilen in druge materiale. Učinkovitost različnih materialov proti tvorbi AFB1 je boljša z dodatkom eteričnih olj in aktivnih spojin. Zaradi okolju prijaznih lastnosti v zadnjem času vse bolj prihajajo v veljavo naravni užitni premazi za živila, kot sta hitozan in želatina s karboksimetil celulozo, ki sta prav tako učinkovitejša z dodatkom eteričnih olj. Tvorbo AFB1 lahko upočasnimo tudi s pakiranjem v atmosfero s spremenjeno plinsko sestavo (MAP). Aflatoxin B1 (AFB1) is a toxic secondary metabolite synthesized by different Aspergillus strains. Its harmful properties represent a serious problem to human health. Additionally, it causes serious economic damage in agriculture and food industry. AFB1 can be found in corn, rice, tree nuts, peanuts and dried fruits and can be produced before or during storage. An effective way to control AFB1 in foods is choosing a suitable method for packaging. Some of the polymer materials represent a barrier for gases and moisture, the major factors that have influence on growth of molds. Such polymers are polyethylene-laminated aluminium, ethylene vinyl alcohol, polypropylene and other materials. The effectiveness of different materials against the formation of AFB1 can be increased by adding essential oils and other active compounds. Edible food coatings like chitosan and carboxymethyl cellulose-gelatin film have recently become popular due to their environmentally friendly properties which also become more effective by addition of essential oils. The synthesis of AFB1 can be controlled by modified atmosphere packaging (MAP) as well.

The results of the research into the microbiological contamination of litter used by broiler chickens are presented. Litter samples were taken prior to the introduction of chicks (day 0) and in 7-day intervals until the end of the fattening period. The total numbers of aerobic mesophilic microorganisms, yeasts, moulds and Clostridium perfringens spores, and the presence of bacteria of the Salmonella genus were determined. The total microbial count in newly laid litter was 7 log10 CFU/g, which increased to 9 log10 CFU/g by the 4th week. However, at the end of the 5th week, it was at the same level as in newly laid litter. C. perfringens spores, presumably originating from chicks' faeces, were first detected on day 7. In the next 7 days their number increased, reaching 3-4 log10 CFU/g, and remained at approximately same levels until the end of the research. The initial mould contamination was 5-6 log10 CFU/g. However, from day 21 moulds were not isolated, but only yeasts of the Saccharomyces genus. It is supposed that these were deposited with chicks' faeces, due to their presence in complete broiler feed. No bacteria of the Salmonella genus were ever isolated from the litter. In conclusion, the total numbers of microorganisms in deep litter reach their peak in approximately a month, which is followed by their decrease. Deep litter is a favourable environment for probiotic yeast cultures. Added to feed intended for broilers, they can positively influence the microbial composition of litter, providing healthier environment to fattening broilers. U radu su prikazani rezultati ispitivanja mikrobiološke kontaminacije prostirke korišćene u tovu pilića. Prostirka je uzorkovana pre naseljavanja objekata i u nedeljnim intervalima tokom 35 dana tova pilića. Uzorci su ispitani na ukupan broj aerobnih mezofilnih mikroorganizama, kvasaca, plesni i spora Clostridium perfringens, kao i prisustvo bakterija roda Salmonella. Ukupan broj mikroorganizama u svežoj prostirci iznosio je 7 log10 CFU/g, a do 4 nedelje tova pilića povećao se do 9 log10 CFU/g. Međutim, na kraju pete nedelje tova, ukupan broj mikroorganizama u prostirci bio je na nivou vrednosti ustanovljenih u svežoj prostirci. Spore C. perfringens su ustanovljene tek sedmog dana od naseljavanja objekta, što ukazuje da u prostirku dospevaju fecesom pilića. Za 14 dana broj spora C. perfringens se povećao do 3-4 log10 CFU/g i na približno istim vrednostima zadržao do kraja ispitivanja. Sveža prostirka bila je kontaminirana plesnima u nivou od 5-6 log10 CFU/g, ali od 21. dana iz uzoraka prostirke nisu izolovane plesni, već samo kvasci roda Saccharomyces. Pretpostavka je da su kvasci u prostirku dospeli fecesom pilića, jer se koriste kao probiotske kulture u smešama za njihov tov. Bakterije roda Salmonella nisu izolovane iz prostirke. Rezultati ispitivanja pokazuju da ukupan broj mikroorganizama u prostirci dostiže svoj pik za oko mesec dana, nakon čega se smanjuje. Prostirka je pogodna sredina za život probiotskih kultura kvasaca i njihovo dodavanje u smeše za tov brojlera može imati povoljan uticaj na sastav mikroorganizama u prostirci, a time i obezbeđenje zdravije životne sredine u podnom sistemu uzgoja brojlera.

V diplomski nalogi smo želeli preveriti protimikrobno učinkovitost etanolnih izvlečkov rastlin Ecballium elaterium in Cucurbita pepo na izbrane bakterije in plesni. Ovrednotili smo inhibicijo rasti po Gramu pozitivne bakterije (Staphylococcus aureus), po Gramu negativne bakterije (Escherichia coli) ter dveh mikotoksigenih plesni (Aspergillus flavus and A. niger). Testirali smo etanolni izvleček plodu E. elaterium ter etanolni izvleček posušene in zmlete bučne pogače C. pepo z uporabo metode mikrodilucije na mikrotitrski plošči. Določili smo minimalno inhibitorno koncentracijo (MIK) obeh pripravljenih izvlečkov. Rezultati so pokazali, da je etanolni izvleček plodu E. elaterium bolje zaviral obe bakteriji in plesni v primerjavi z bučno pogačo, za katero so bile potrebne višje koncentracije. Etanolni izvleček plodu E. elaterium je po Gramu pozitivno bakterijo S. aureus zaviral z minimalno koncentracijo 1,5–1,75 mg/ml, po Gramu negativno bakterijo E. coli pa z MIK več kot 3,5 mg/ml. MIK istega izvlečka za mikotoksigeno plesen A. niger je znašal 37,5–75 mg/ml, za plesen A. flavus pa 4,6–9,4 mg/ml. Pri preizkušanju etanolnega izvlečka zmlete in posušene bučne pogače nismo natančno določili minimalne inhibitorne koncentracije zaradi otežene priprave izvlečka višje koncentracije kot 150 mg/ml. Pokazalo se je, da za inhibicijo rasti po Gramu negativne bakterije potrebujemo višje koncentracije obeh izvlečkov, prav tako kot za inhibicijo plesni. In the thesis we wanted to determine the antimicrobial efficacy of plant extracts from Ecballium elaterium and Cucurbita pepo against selected bacterial and fungal species. We evaluated the growth inhibition of the Gram positive bacterium (Staphylococcus aureus), the Gram negative bacterium (Escherichia coli) and two mycotoxigenic molds (Aspergillus flavus and A. niger). We tested the ethanol extract of E. elaterium fruit and ethanol extract of C. pepo dried and ground pumpkin oil cake using microdilution method on a microtiter plate. The minimum inhibitory concentration (MIC) of both extracts was determined. Results showed that the ethanol extract of E. elaterium fruit expressed better growth inhibition of both bacteria and molds compared to pumpkin oil cake extract, which required higher concentrations. The ethanol extract of E. elaterium inhibited a Gram positive S. aureus with minimal inhibitory concentration 1,5–1,75 mg/ml and a Gram negative E. coli with MIC more than 3,5 mg/ml. MIC of the same extract on micotoxigenic mold A. niger was 37,5–75 mg/ml and 4,6–9,4 mg/ml for A. flavus. In the experiment the MIC of the ground and dried pumpkin oil cake ethanol extract was not determined precisely, due to the difficulty of preparing concentration of the extract higher than 150 mg/ml. The research showed that higher concentrations of both extracts are required for growth inhibition of Gram negative bacteria as well as for molds.

Namen diplomskega dela je bil ugotoviti, ali izbrana eterična olja (EO) delujejo protiglivno. Zato smo jim določili minimalno inhibitorno koncentracijo (MIC) ter minimalno mikrobicidno koncentracijo (MBC) ter njihovo delovanje primerjali z že uveljavljenim razkužilom – vodikovim peroksidom. Testirali smo EO origana (Origanum vulgare), grške bazilike (Ocimum basilicum), sladkega pelina (Artemisia annua), sivke (Lavandula hybrida), laškega smilja (Helichrysum italicum), rožmarina (Rosmarinus officinalis), nemške kamilice (Matricaria recutita) in žajblja (Salvia officinalis) ter vodikov peroksid s kvasovkami vrste Candida albicans in plesnimi vrste Penicillium griseofulvum. Za testiranje protiglivne aktivnosti smo uporabili metodo razredčevanja v mikrotitrski ploščici. Natančne vrednosti MIC in MBC smo za kvasovke določili z metodo štetja kolonij na trdnem gojišču, za plesni pa s pregledovanjem gojišča s plesnimi v mikrotitrskih ploščicah pod lupo. Kvasovke vrste C. albicans so bile bolj dovzetne za EO kot plesni vrste P. griseofulvum. Kvasovkam smo vrednosti MIC določili v območju

Plesni pogosto povzročajo kvarjenje različnih vrst živil, saj lahko rastejo na raznolikih substratih. Mednje spadajo tudi pekovski izdelki. Plesnenje pekovskih izdelkov povzroča veliko ekonomsko škodo pekarnam in zdravstveno tveganje za potrošnike. Zaviranje oziroma upočasnitev tega procesa lahko dosežemo s kemijskimi konzervansi, a so ti nezaželjeni s strani potrošnikov, ki dajejo prednost hrani brez aditivov. Zato raziskovalci iščejo naravne alternative uporabe konzervansov. V tej diplomski nalogi smo testirali učinek 10 %-nega dodatka, pripravljenega iz različnih stranskih proizvodov živilske industrije (grozdnih tropin belega in rdečega grozdja, oljčne pogače, lanene pogače, bučne pogače, pivovarskih tropin in rožiča) beli pšenični moki na zaviranje rasti plesni na kruhu. Naredili smo mikrobiološko preiskavo sredice vzorcev kruha po peki in obremenitveni test s štirimi sevi plesni rodov Aspergillus in Penicillium, ki pogosto rastejo na kruhu. Rezine kruha smo inokulirali z določeno koncentracijo spor plesni, nato pa spremljali dinamiko plesnenja kruha tekom enega tedna. Noben dodatek ni vplival na mikrobiološko sliko sredice kruha po peki. Pri obremenitvenem testu pa so nekateri dodatki zavirali rast plesni, nekateri pa so jo celo spodbujali. Dodatka, ki sta najbolj zavirala rast izbranih plesni, sta bili moki, pripravljeni iz rožiča in bučne pogače, pri vseh testiranih plesnih. Dodatka moke lanene pogače in oljčne pogače sta spodbudila rast plesni Molds are common spoilage microorganisms in many types of foods because they can easily grow on different substrates. Bakery products are among them. Molding of bakery products causes economical loss for bakeries and health risk for consumers. Preservatives can slow down this process, but lately they are avoided by consumers, because they give priority to food without additives. That is why scientists are working a lot on finding natural alternatives which could replace preservatives. In this bachelor thesis we tested the effect of addition of food industry by-products (grape pomace from red and white grapes, olive pomace, flaxseed oil cake, pumpkin oil cake, brewer's spent grain and carob flour) to white wheat flour in concentration of 10 % to prevent molding on bread. We did the microbiological examination of the inside of bread samples after baking and the challenge test with four strains of genera Aspergillus and Penicillium, which commonly grow on bread. We inoculated samples with a certain concentration of mold spores and kept track of their growth kinetics during one week. No by-product had an influence on the microbiological quality of the inside of the bread samples after baking. In the challenge test the addition of some by-products inhibited mold growth, some stimulated it. Wheat flours mixed with carob flour and pumpkin oil cake slowed down the growth of all tested molds. The addition of flaxseed cake and olive pomace generally accelerated the growth kinetics of molds.

Dodatek vlaken sladkorne pese (5 in 10 %) izboljša prehransko vrednost belega pšeničnega kruha, a ima negativen učinek na reološke lastnosti testa in senzorične lastnosti kruha. Povečana vsebnost vode negativno vpliva tudi na mikrobiološko obstojnost kruha. Zato smo za izboljšanje tehnoloških lastnosti testa, ki smo jih določali s farinografsko, ekstenzografsko in maturografsko metodo, ter senzoričnih lastnosti in obstojnosti kruha, uporabili še rožičevo moko (7,5 in 15 %) in melaso (3 in 6 %). Ugotovili smo, da melasa (6 %) povečuje elastičnost in raztegljivost testa in deluje protimikrobno. Rožičeva moka je bogata z bioaktivnimi snovmi, poveča vsebnost skupnih fenolnih spojin in antioksidativno kapaciteto v vodi topnih antioksidantov kruha. Na reološke lastnosti testa nima negativnega vpliva. Z dodatkom melase in rožičeve moke pridobimo velik končni volumen in najboljše senzorične lastnosti kruha. Dodatek rožičeve moke zmanjšuje skupno število aerobnih bakterij kruha in preprečuje pojavnost bakterij Bacillus cereus. Melasa, rožičeva moka in njuna kombinacija izboljšujeta mikrobiološko obstojnost rezin kruha celo učinkoviteje od konvencionalnega konzervansa. Protimikrobno delovanje z zaviranjem rasti plesni smo potrdili tako s testom obstojnosti, kot z obremenitvenimi testi s plesnimi Aspergillus flavus, Penicillium verrucosum in Cladosporium sp.. Fortification of white wheat bread with sugar beet fibers (5 and 10 %) improves a nutritional value of bread, but has a negative effect on dough rheoloy, sensory properties and shelf-life of bread due to higher water content. For this reason, we have included carob flour (7,5, 15 %) and sugar beet molasses (3, 6 %) as partial replacement of wheat flour. We have enhanced technological properties of dough, determined by farinograph, extensograph and maturograph measurements. Molasses (6 %) improved dough elasticity and extent. Carob flour is rich in bioactive components and increased total phenol content and antioxidative capacity of bread. It had no adverse effect on dough rheology. Combined addition of molasses and carob flour increased volume and improved sensory properties of bread. Carob flour decreased total aerobic mesophilic count and sporogenic bacteria, as well as prevented Bacillus cereus presence in bread. Molasses, carob flour and their combination prolonged shelf-life of bread, even more effectivelly than a conventional preservative. Antifungal activity has been confirmed by bread shef-life test and challenge tests with Aspergillus flavus, Penicillium verrucosum in Cladosporium sp..

Glavnina rasti in tvorbe toksinov skladiščnih plesni poteka po spravilu pridelka, vendar pridejo plesni v stik z rastlinami že na polju ali ob spravilu pridelka. Najpomembnejše vrste skladiščnih plesni spadajo v rodova Aspergillus in Penicillium. Glavni predstavnici iz rodu Aspergillus sta glivi A. flavus in A. parasiticus. Obe lahko tvorita AFB1 in AFB2. Iz omenjenega rodu poznamo še skladiščne plesni vrst A. ochraceus, A. westerdijkiae, A. steynii, A. carbonarius in A. niger, ki lahko tvorijo ohratoksine, vendar žita redko okužijo. Edini odkriti vrsti gliv iz rodu Penicillium, ki lahko tvorita ohratoksine, sta P. verrucosum in P. nordicum. P. verrucosum je bolj pogosta skladiščna plesen in jo najdemo izključno na žitu. Tvorba toksinov za glive ni esencialnega pomena in se začne ob za glivo stresnih pogojih. Mikotoksini so škodljivi zdravju ljudi in živali. Nekateri izmed njih so rakotvorni. Glavni predstavniki mikotoksinov, ki jih najdemo na žitu in žitnih izdelkih, so aflatoksini in ohratoksini. Glavni ukrep za zaviranje rasti skladiščnih plesni in tvorbe mikotoksinov je zagotavljanje ustreznih skladiščnih pogojev. Potrebno je uravnavanje temperature in vlage. Koristen preventivni ukrep za zagotavljanje higienske neoporečnosti hrane in krme je tudi čiščenje luske zrnja in ločevanje primesi, poškodovanih in plesnivih zrn od navidezno zdrave žitne mase. Most of the growth and mycotoxin production of the storage molds takes place after the harvesting, but the mold comes into contact with plants already in the field or at harvesting.. The most important storage fungi species originate from genuses Aspergillus and Penicillium. The major two species from Aspergillus genus are A. flavus and A. parasiticus. Both can produce AFB1 and AFB2. A. ochraceus, A. westerdijkiae, A. steynii, A. carbonarius and A. niger are also known as storage fundi. They all can produce ochratoxins, but we rarely find them on grains. The only known ochratoxin producing species from Penicillium genus are P. verrucosum and P. nordicum. P. verrucosum is more common from the two and we typically find it on grains. Mycotoxin production isn’t essential. It starts when fungi are in stress. Mycotoxins can harm human and animal health. Some of them are cancerogenic. The most important mycotoxins found on grains and grain products are aflatoxins and ochratoxins. The major strategy for reducing fungal growth and mycotoxin production is providing adequate storage facilities. Controlling temperature and humidity is necessary. An useful measure for providing pristine food and feed is rinsing the grains surface and sorting foreign particles, moldy or damaged grains from healthy looking grain mass.

U ovom radu ispitivane su hemijska i nutritivna svojstva polena koji su sakupile medonosne pčele i to: palinološko poreklo uzoraka polena, sadržaji pepela, vlage, makro‐ i mikroelemenata, energetska vrednost, ukupni sadržaji proteina, ugljenih hidrata, lipida i fenola, ukupni antioksidativni kapacitet kao i pojedinačni sadržaji rastvorljivih ugljenih hidrata, masnih kiselina i fenolnih jedinjenja. Osim toga, ispitano je i prisustvo plesni i aflatoksina B1, kao mikrobiološki parametar ispravnosti uzoraka kao i tehno‐funkcionalnih svojstava: peniva i emulgujuća svojstva, rastvorljivost proteina i ugljenih hidrata, kapaciteti vezivanja vode i ulja. Utvrđeno je da se uzorci razlikuju po botaničkom poreklu, da je većina polifloralnog tipa sa petnaest zastupljenih biljnih vrsta i rodova od kojih su najzastupljeniji bili krstašice (kupusnjače) (Brassicaceae) i mahunarke (Fabaceae). Sadržaj vlage u ispitivanim uzorcima se kretao u opsegu od 4,35 do 14,35 g/100g dok je sadržaj pepela bio u intervalu 1,18‐3,32 g/100g. Na osnovu sadržaja ukupnih proteina (14,81‐27,25%), ugljenih hidrata (64,42‐81,84%), lipida (1,31‐ 6,78%) i prosečne energetske vrednosti (375 kcal) zaključeno je da bi se polen koji su sakupile medonosne pčele mogao koristiti kao dodatak ishrani. Na osnovu sadržaja pojedinačnih rastvorljivih ugljenih hidrata utvrđeno je da je, u najvećem broju uzoraka, najzastupljeniji šećer fruktoza. Osim nje identifikovane su i glukoza, maltoza, saharoza i trehaloza. Od pojedinačnih masnih kiselina u uzorcima polena identifikovano ih je dvadeset, od čega je šest zastupljeno u svim uzorcima – C8:0, C16:0, C18:0, C18:1n‐9, C18:2n‐6 i C18:3n‐3. Na osnovu kvantitativne analize ukupnog sadržaja fenolnih jedinjenja (25,82 ‐ 206,09 mg/100g) za većinu uzoraka se moglo reći da su sadržavali male količine fenolnih jedinjenja. U svim uzorcima identifikovana su četiri od ukupno trinaest prisutnih fenolnih jedinjenja – rutin, luteolin, galna i hlorogena kiselina. Ukupni antioksidativni kapacitet ispitivanih uzoraka se kretao u opsegu od 27,46 do 138,89 mmol kg‐1 TROLOX‐a... In this study chemical and nutritional characteristics of bee‐collected pollen have been determined: palynological origin of samples, ash, moisture, macro and microelements content, as well as energetic value and total content of proteins, carbohydrates, lipids and fenolic compounds as well as total antioxidative capacity. Furthermore, contents of soluble sugars, fatty acids and phenolic compounds have been estimated. Presence of moulds and aflatoxin B1 has been investigated as well as techno‐functional properties such as: of protein and carbohydrate solubility, foaming and emulsifying properties, water and oil absorption capacity. It was found that most of the samples were polyfloral with different palynological origin represented by fifteen plant families or species. The most abundant families were Brassicaceae and Fabaceae. The moisture content was ranged from 4.35 to 14.35 g/100g, while content of ash varied in the range: 1.18 ‐ 3.32 g/100g. Based on the total protein (14.81 to 27.25%), carbohydrate (64.42 to 81.84%) and lipid (1.31 to 6.78%) contents and the average energy value (375 kcal), it was concluded that bee‐collected pollen could be used as a dietary supplement. Among soluble carbohydrates the most abundant sugar was fructose. In addition glucose, sucrose, maltose and trechalose were found. Twenty fatty acids were detected in samples wherein six were found in all of the investigated samples‐ C8:0, C16:0, C18:0, C18:1n‐9, C18:2n‐6 i C18:3n‐3. Based on the total content of phenolic compounds (25.89 ‐ 206.09 g/100g) most of the samples were characterized by low level. Four of the thirteen detected phenolic compounds were found in all samples‐ rutin, luteolin, galic and chlorogenic acid. Total antioxidative capacity was ranged from 27.46 to 138.89 mmol kg‐1 of TROLOX. On the basis of the content of macro‐ and microelements, it was concluded that the three most common elements in samples of pollen were potassium, calcium...

S problemom nastajanja plesni in prekomerne vlage se soočamo tako v bivalnih kot tudi delovnih in drugih prostorih. Naš namen je bil preučiti zakonodajo z vidika kondenzacije, posebej pa smo se osredotočili na standarda SIST EN ISO 13788:2002 in SIST EN ISO 13788:2013. Standard SIST EN ISO 13788:2002 opisuje metode za izračun notranjih temperatur na površini konstrukcijskih sklopov ali sestavnega dela konstrukcijskega sklopa, pod katero nastaja plesen, in ocene tveganja kondenzacije zaradi difuzije vodne pare. Preučili pa smo tudi prenovljeni standard, SIST EN ISO 13788:2013, ki ima dodan še primer določitve notranje temperature zraka in relativne zračne vlažnosti, vsebuje pa tudi primere izračunov konstrukcijskih sklopov, ki vsebujejo vmesne zračne plasti, in primer izračuna izsuševanja vlage, ki je bila vnesena med izvedbo konstrukcijskega sklopa. Na osnovi omenjene dokumentacije smo izdelali program in ga poimenovali PIDVP. Program omogoča izračun difuzije vodne pare in ocene tveganja nastanka plesni ter nastajanja kondenzacije na površini in znotraj konstrukcijskega sklopa. Prav tako smo vključili tudi izračune za določitev notranje temperature in vlažnosti zraka. Pomagalo ne vsebuje možnosti izračuna za primer konstrukcije, ki vsebuje zračne plasti in izračuna za določitev časa izsuševanja vlage, ki je bila vgrajena med izgradnjo konstrukcije. Vsi primeri izračunov iz standarda SIST EN ISO 13788:2002 so bili ponovno izračunani s pomočjo tega programa. Dva dodatna primera (za streho in za steno) sta bila izračunana s pomočjo izdelanega programa ter programa KI Energija 2014. Primerjava izračunov je prikazana v preglednicah, kjer je posebej izpostavljeno ujemanje rezultatov. Ugotovljeno je bilo, da pri primerjavi rezultatov prihaja do zanemarljivih odstopanj. Le v dodatnem primeru za steno prihaja pri izračunu stopnje kondenzacije v mesecu aprilu do večjih odstopanj med rezultati novo izdelanega programa (program predvideva, da v eni od ravnin še vedno prihaja do kondenzacije) in rezultati programa KI Energija 2014 (program predvideva, da v isti ravnini poteka izsuševanje kondenzirane vodne pare). Na podlagi analize primerjav izračunov lahko sklepamo, da novo izdelani program deluje pravilno. Po analizi, ki je opisana, predvidevamo, da je do odstopanja v mesecu aprilu prišlo le zaradi drugačnega načina izračuna stopnje kondenzacije. Mould growth and excess moisture pose problems in residential as well as working and other spaces. Our purpose was to study legislation regarding condensation, in particular the SIST EN ISO 13788:2002 and SIST EN ISO 13788:2013 standards. SIST EN ISO 13788:2002 standard describes calculation methods for the internal surface temperatures of a building component or building elements below which mould growth is likely as well as risk assessment of condensation due to water vapour diffusion. We have also studied the revised SIST EN ISO 13788:2013 standard which includes an example of determining internal air temperature and relative air humidity as well as examples for calculating building components which contain intermediary air layers and an example of calculating the drying of moisture which was generated during the execution of the building component. On the basis of the aforementioned documentation, we have devised a programme and named it PIDVP. The programme enables the calculation of water vapour diffusion as well as an assessment for the risk of mould growth and condensation formation on the surface and inside the building component. We have also included calculations for determining internal temperature and air humidity. The tool does not include the possibility to make calculations for a construction which contains air layers and calculations to determine the drying time of moisture which was generated during the construction. All examples of calculations from the SIST EN ISO 13788:2002 standard have been recalculated with the help of this programme. Two additional examples (for the roof and wall) were calculated with the help of the devised programme and KI Energija 2014 programme. The comparison of calculations is shown in the tables which particularly display the compliance of the results. It has been determined that there were only negligible deviations when comparing the results. There were bigger deviations only in the additional example for the wall when calculating the level of condensation in April if we compare the results of the newly devised programme (which foresees the condensation formation in one of the planes) and the results from KI Energija 2014 programme (which foresees the drying of the condensed water vapour in the same plane). On the basis of the calculation comparisons analysis, it can be concluded that the newly developed programme works correctly. According to the described analysis we can conclude that the deviations in the month of April were only due to a different method of condensation level calculation.

Namen naloge je spremljati biosintezno stabilnost plesni ▫{sl M. miehei}▫ pri proizvodnji ekstracelularnih proteaz in ugotoviti vpliv Uv sevanja na sposobnost biosinteze koagulativnega encima. Stabilnost biosinteze smo testirali pri polisporni kulturi, monokulturah A, B, C in D, ki smo jih vzgojili iz polisporne kulture, in pri petih mutantih ▫{sl M. miehei}▫ MB v različnihčasovnih intervalih. Ugotovili smo, da so delovne kulture stabilne pri biosintezi koagulativnega encima. Polisporna kultura dosega encimsko aktivnost 2265,9 E/ml do 2561,1 E/ml. Monokulture B, C in D so si po encimski aktivnosti zelo podobne. Vrednosti encimske aktivnosti se gibljejo od 2136,3 E/ml do 2270,1 E/ml. Odstopa monokultura A, ki ima zelo nizko encimsko aktivnost 100,1 E/ml. Po izvedbi mutacije dobimo mutante plesni ▫{sl M. miehei}▫ MB, ki imajo izraženo biosintezno sposobnost produkcije koagulativnega encima.

Incidence of toxigenic fungi (molds) and concentration of mycotoxin aflatoxin B1 (AFB1), deoxynivalenol (DON), zearalenone (ZON) and fumonisin (FB1) were studied in the maize grains collected immediately after harvesting in 2012. A total of 29 maize samples were analyzed and the highest incidence was determined for fungal species of Rhizopus (56.41%), Aspergillus (43.66%) and Fusarium (14.97%) genera. Significantly lower incidence was obtained for species of genus Penicillium (3.31%), and especially for species of genera Acremonium (1.38%), Alternaria (0.75%) and Cladosporium (0.14%). Among toxigenic fungi Aspergillus flavus (36.69%) was the most common species of Aspergillus genus, whereas the Fusarium verticillioides with 14.69% of incidence was the predominant species of Fusarium genus. In all studied maize samples, the presence of AFB1, ZON and FB1 mycotoxins was established, except for DON which was established in 75.86% samples. AFB1 was detected in average concentration of 13.95 μg kg-1 for 44.83% of samples, and average concentration higher than 40 μg kg-1 for 55.17% of samples. The average concentrations of DON which was detected was 235 μg kg-1, while it was 98.38 μg kg-1 and 3590 μg kg-1 for the presence of ZON and FB1, respectively. Moderate positive correlation was obtained between concentrations of AFB1 and FB1 (r=0.35), while weak positive correlation was established between concentrations ZON and DON (r=0.02). Učestalost toksigenih gljiva (plesni) i koncentracija mikotoksina aflatoksina B1 (AFB1), deoksinivalenola (DON), zearalenona (ZON) i fumonizina B1 (FB1) je proučavana u uzorcima zrna kukuruza prikupljenim odmah posle berbe u 2012. godini. U ispitivanih 29 uzoraka najveću zastupljenost imaju vrste iz rodova Rhizopus (56,41%), Aspergillus (43,66%) i Fusarium (14,97%). Značajno niža učestalost ustanovljena je za vrste roda Penicillium (3.31%), a posebno za vrste iz rodova Alternaria (0,75%) i Cladosporium (0,14%). Među toksigenim vrstama, A. flavus (36,69%) je bila najučestalija vrsta iz roda Aspergillus, dok je F. verticillioides sa prisustvom od 14,69% bila dominantna vrsta roda Fusarium. U svim ispitivanim uzorcima kukuruza ustanovljeno je prisustvo mikotoksina AFB1, ZON-a i FB1 (100%), osim DON-a koji je bio prisutan u 75,86% uzoraka. AFB1 je detektovan u prosečnoj koncentraciji od 13,95 μg kg-1 u 44,83% uzoraka i u prosečnoj koncentraciji od više od 40 μg kg-1 u 55,17% uzoraka. Prosečna koncentracija DON-a je bila 235 μg kg-1, ZON-a 98,38 μg kg-1 i FB1 3590 μg kg-1. Srednja pozitivna korelacija ustanovljena je između koncentracija AFB1 i FB1 (r=0,35), dok je slaba pozitivna korelacija utvrđena između koncentracija ZON-a i DON-a (r=0,02).

Aerobic stability is a term that indicates the length of the time that silage remains cool and does not spoil after it is exposed to air. Therefore, rapid removal of air from forage mass and prevention of air infiltration into the silage during storage and feed out are the important factors that determine the duration of the silage aerobic stability. The measurement of CO2 production, separately or in combination with other measurements such as temperature, pH, lactic acid and volatile fatty acids and microbial examination, can serve as a reliable laboratory method to determine the duration of silages aerobic stability in silages. This paper work has aim to point on the importance of determination the duration of aerobic stability of silages, because quality changes and losses in the case of aerobic degradation. Aerobna stabilnost je termin kojim se definiše dužina vremena za koje silaža ostaje hladna i ne kvari se po izlaganju vazduhu. Zbog toga, brzo otklanjanje vazduha iz silaže tokom siliranja i smanjeno izlaganje vazduhu po otvaranju silosa su dva važna faktora koji određuju dužinu aerobne stabilnosti silirane stočne hrane. U proceni aerobnog kvarenja,merenje proizvodnje CO2, odvojeno ili u kombinaciji sa drugim parametrima kao što je temperatura silaže, pH vrednost, sadržaj mlečne i sirćetne kiseline i mikrobiološka analiza, mogu se koristiti kao pouzdani laboratorijski metod. Ovaj rad ima za cilj da ukaže na značaj procene vremena trajanja aerobne stabilnosti stočne hrane,zbog promena i gubitaka kvaliteta pri aerobnoj degradaciji.

Cilj istraživanja doktorske disertacije bio je da se ispita pojedinačni i sinergistički uticajekstrakata kima (Carum carvi L.), bosiljka (Ocimum basilicum L.), origana (Origanumvulgare L.) i etarskih ulja crnog (Allium cepa L. kultivar Kupusinski jabučar) i belog luka(Allium sativum L. kultivar Bosut) na rast plesni izolovanih iz prehrambenih proizvoda, kao injihov uticaj na biosintezu mikotoksina.Ukupan broj plesni u uzorcima salata od povrća spremnih za konzumiranje kretao se od10,0 do 5,5´102 cfu/g, u uzorcima poslastičarskih proizvoda do 6,1´102 cfu/g i uproizvodima od mesa do 60,0 cfu/g. Najveći broj plesni izolovan je na DG18 podlozi(1,53´102 cfu/g), a najmanji na MY50G (42,0 cfu/g). U ukupnoj mikopopulaciji svih ispitivanihuzoraka dominirale su vrste rodova Penicillium (39,07%), Cladosporium (23,40%) iAspergillus (20,42%). Vrste iz rodova Alternaria, Fusarium i Eurotium su bile zastupljene sa5,85%, 4,97% i 2,76%. Dominantne vrste u ukupnoj mikopopulaciji bile su C.cladosporioides (21,63%), A. niger (16,0%) i P. aurantiogriseum (11,81%).Dominirali su potencijalni producenti ohratoksina A (31,89%), proizvoñači fumonizina(4,74%), moniliformina (1,43%) i sterigmatocistina (1,54%). Izolati A. versicolor subiosintetisali sterigmatocistin u koncentracijama od 56,3 i 109,2 ng/mL. Ostale potencijalnetoksin-produkujuće vrste nisu pokazale sposobnost produkcije mikotoksina.Mikotoksikološkim ispitivanjem hrane u dva uzorka salata spremnih za konzumiranje(kupus beli rezani i FIT salata) utvrñen je sadržaj sterigmatocistina u koncentracijama od 3,5i 5,5 mg/kg.Kao glavna komponenta u ekstraktu kima odreñen je karvon (43,98%), u ekstraktu bosiljkaestragol (metil kavikol) (86,72%), a u ekstraktu origana karvakrol (34,20%) i karvon (18,05%).Najveći deo etarskog ulja crnog luka činili su: dimetil-trisulfid, metil-propil-trisulfid, dimetiltetrasulfid,dietil-1,2,4-tritiolan, metil-(1-propenil)-trisulfid, metil-(1-propenil)-disulfid. Dialildisulfid,dialil-trisulfid, metil-alil-trisulfid i metil-alil-disulfid su glavne komponente koje suodreñene u etarskom ulju belog luka.Koncentracija od 0,35 mL/100 mL ekstrakta kima je bila fungicidna (MFC) prema C.cladosporioides, dok je 0,70 mL/100 mL potpuno inhibirala rast A. carbonarius, A. wentii, E.nidulans, Eurotium spp., C. cladosporioides, P. glabrum, P. brevicompactum, F.subglutinans i F. verticillioides. Na rast P. chrysogenum i P. aurantiogriseum istakoncentracija bila je inhibitorna (MIC). Najslabije delovanje ovaj ekstrakt ispoljio prema A.niger, A. versicolor, F. oxysporum i F. proliferatum.Primena ekstrakta bosiljka u koncentraciji od 0,70 mL/100 mL pokazala je fungicidnodelovanje na C. cladosporioides. Koncentracija od 1,50 mL/100 mL potpuno je inhibiralarast A. wentii, A. versicolor, E. nidulans, E. herbariorum, E. chevalieri, E. rubrum, P.chrysogenum i Fusarim spp. Ekstrakt bosiljka je najslabije delovao prema A. niger, A.carbonarius, P. aurantiogriseum, E. amstelodami, P. glabrum i P. brevicompactum.Ekstrakt origana je pokazao najslabije ihibitorno delovanje na rast ispitivanih plesni.Primena ekstrakta u koncentraciji od 1,50 mL/100 mL je bila fungicidna prema E. rubrum.Koncentracija od 2,50 mL/100 mL je pokazala fungicidno delovanje na E. rubrum, E.herbariorum, A. wentii, C. cladosporioides i P. aurantiogriseum, a inhibitorno prema E.nidulans, E. chevalieri, E. amstelodami, P. glabrum i P. brevicompactum. Ovaj ekstrakt jenajslabije delovao na A. niger, A. carbonarius, F. proliferatum, F. subglutinans i P.chrysogenum.Etarsko ulje crnog luka pokazalo je signifikantno jače antifungalno delovanje na ispitivaneplesni u odnosu na etarsko ulje belog luka. Koncentracija od 14,0 mL/100 mL ulja belog lukafungicidno je delovala prema E. rubrum, E. chevalieri i C. cladosporioides, dok je ulje crnogluka na ovoj koncentraciji pokazalo fungicidni efekat i na E. herbariorum i E. amstelodami.Za ostale plesni fungicidna koncentracija iznosila je 28,0 mL/100 mL, osim za A. niger i P.aurantiogriseum.Neke od ispitivanih smeša bosiljka i kima, bosiljka i origana, origana i kima i etarskih uljalukova pokazale su sinergističko delovanje na inhibiciju rasta A. wentii, E. herbariorum, F.verticilllioides i P. aurantiogriseum sa FICindex od 0,63 do 0,97.Začinski ekstrakti i etarska ulja lukova su pored ograničavanja rasta kolonija plesniuzrokovali i promene u makro i mikromorfologiji.Potpuna inhibicija biosinteze sterigmatocistina i rasta A. versicolor postignuta je prikoncentraciji od 0,20 mL/100 mL ekstrakta kima i origana u periodu od 21 dana. Na ovojkoncentraciji ekstrakt bosiljka je inhibirao biosintezu sterigmatocistina za 88,73% i rastplesni za 52,56%. Smeša koja je sadržavala 75% ekstrakta kima i 25% ekstrakta bosiljkapotpuno je inhibirala rast plesni i biosintezu sterigmatocistina u YES bujonu tokom 21 danainkubiranja.Pojedinačne koncentracije etarskih ulja crnog i belog luka od 5,0 i 10,0 mL/100 mL i u smešisa 1,50 mL/100 mL etarskog ulja crnog luka i 0,50 mL/100 mL etarskog ulja belog luka bile supotrebne za potpunu inhibiciju rasta A. versicolor i biosintezu sterigmatocistina.Dodatak smeše ekstrakata kima i bosiljka (0,35 mL/100 mL ekstrakta kima + 0,70 mL/100 mLekstrakta bosiljka) u svež kupus rezanac uticao je na smanjenje inicijalne kontaminacijeplesnima za 93,9%, uz pojavu intenzivnijeg, ali prihvatljivog mirisa i neznatne promene boje.Definisani matematički model za komparaciju uticaja ekstrakata i etarskih ulja na rast plesnimože se primenjivati u formiranju matrica inhibicije i optimizaciji vremena i koncentracijeantifungalnih agenasa.Dobijena saznanja o antifungalnom delovanju ekstrakata začina i etarskih ulja lukova mogubiti značajna u poboljšanju antifungalne zaštite namirnica, smanjenju biosintezemikotoksina i ukupnim smanjenju šteta izazvanih delovanjem plesni., The aim of this PhD thesis was to study the individual and synergistic effects of extracts ofcaraway (Carum carvi L.), basil (Ocimum basilicum L.), oregano (Origanum vulgare L.) and theessential oils of onion (Allium cepa L. cultivar Kupusinski jabučar) and garlic (Allium sativumL. cultivar Bosut) on the growth of moulds isolated from food products. The study alsofocused on the impact of extracts and the essential oils on mycotoxins biosynthesis.The total number of moulds detected in samples of vegetable salads “ready for use” rangedfrom 10.0 to 5.5´102 cfu/g. In cake and pastries, as well as, meat samples, the numberreached 6.1´102 cfu/g and 60.0 cfu/g, respectively. The highest number of mould colonies wasisolated in DG18 medium (1.53 ´ 102cfu/g) and the lowest in MY50G medium (42.0 cfu/g). Thespecies of the genera Penicillium (39.07%), Cladosporium (23.40%) and Aspergillus (20.42%)prevailed in the entire mycopopulation of all tested samples. Species of the genera Alternaria,Fusarium and Eurotium were represented with 5.85%, 4.97% and 2.76%, respectively, while C.cladosporioides (21.63%), A. niger (16.0%) and P. aurantiogriseum (11.81%) were the mostdominant species in the entire mycopopulation.Potential producers of ochratoxin A (31.89%) accounted for the largest share of the isolatedmycopopulation. The share of producers of fumonisin, moniliformin and sterigmatocystinamounted to 4.74%, 1.43% and 1.54%, respectively. Sterigmatocystin was biosynthesised inthe concentration of 56.3 ng/mL and 109.2 ng/mL by both isolates of A. versicolor, while otherpotential toxin producers did not show the ability of mycotoxin production.Mycotoxicological investigation showed the sterigmatocystin content in two samples ofvegetable salads "ready for use" (shredded white cabbage and FIT salad - carrot, lettuce andred chicory) in concentrations of 3.5 mg/kg and 5.5 mg/kg, respectively.The major component in the extract of caraway was carvon with a share of 43.98%. The basilextract contained estragol (methyl cavicol) in the highest percentage (86.72%), whilecarvacrol (34.20%) and carvon (18.05%) were major components of the oregano extract. As forthe essential oil of onion, dimethyl trisulphide, methyl propyl trisulphide, dimethyl tetrasulfid,diethyl-1, 2, 4-tritiolan, methyl-(1-propenyl)-trisulphide, and methyl-(1-propenyl) – disulfideconstituted the largest share. The major components isolated in garlic essential oil werediallyl disulfide, diallyl-trisulphide, allyl methyl trisulphide and allyl methyl disulfide.The concentration of the caraway extract of 0.35 mL/100mL exhibited fungicidal effect (MFC)on C. cladosporioides, while the concentration of 0.70 mL/100mL completely inhibited thegrowth of A. carbonarius, A. wentii, E. nidulans, Eurotium spp., C. cladosporioides, P.glabrum, P. brevicopmactum, F. subglutinans and F. verticillioides. The same concentrationshowed the inhibitory effect (MIC) on the growth of P. chrysogenum and P. aurantiogriseum.The poorest effect of the caraway extract was expressed on the growth of A. niger, A.versicolor, F. oxysporum and F. proliferatum.The basil extract application in the concentration of 0.70 mL/100mL showed fungicidal effects(MFC) on the growth of C. cladosporioides. The concentration of 1.50 mL/100mL completelyinhibited (MFC) the growth of A. wentii, A. versicolor, E. nidulans, E. herbariorum, E.chevalierii, E. rubrum, P. chrysogenum and Fusarim spp. The poorest effect of the basilextract was exhibited on A. niger, A. carbonarius, P. aurantiogriseum, E. amstelodami, P.glabrum and P. brevicompactum.The oregano extract showed the weakest growth inhibition influence on all of the testedmoulds. The application of this extract in the concentration of 1.50 mL/100mL was fungicidal(MFC) to E. rubrum. The concentration of 2.50 mL/100mL showed fungicidal effects (MFC) onthe growth of E. rubrum, E. herbariorum, A. wentii, C. cladosporioides and P. aurantiogriseumand inhibitory effects (MIC) on E. nidulans, E. chevalieri, E. amstelodami, P. glabrum and P.brevicompactum. The weakest effect of this extract was expressed on the growth of A. niger,A. carbonarius, F. proliferatum, F. subglutinans and P. chrysogenum.Onion essential oil showed a significantly stronger antifungal effect on the tested moulds incomparison to garlic essential oil. While the concentration of 14.0 mL/100mL of garlic oil had afungicidal effect on E. rubrum, E. chevalieri and C. cladosporioides, the same concentrationof onion oil was also fungicidal to E. herbariorum and E. amstelodami. With an exception of A.niger and P. aurantiogriseum, the concentration that showed a fungicidal effect on theremaining moulds equalled 28.0 mL/100mL.Some of the tested mixtures of basil with caraway, basil with oregano, oregano with caraway,and essential oils of onion and garlic, showed a synergistic effect on the growth inhibition ofA. wentii, E. herbariorum, F. verticilllioides and P. aurantiogriseum with the FIC index rangingfrom 0.63 to 0.97.Apart from the inhibitory effect on the mould colony growth, the spices extracts and theessential oils of onion and garlic also caused changes in the macro- and micro- morphologyof the moulds.Complete inhibition of the growth of A. versicolor and sterigmatocystin biosynthesis wasachieved at a concentration of 0.20 mL/100mL of the extract of caraway and oregano in theperiod of 21 days. At this concentration the basil extract delayed the sterigmatocystinbiosynthesis by 88.73% while the mould growth was inhibited by 52.56%. Mixtures containing75% of the caraway extract and 25% of the basil extract completely inhibited the mouldgrowth and sterigmatocystin biosynthesis in YES broth during 21 days of incubation.The concentrations of 5.0 m L/100mL (onion essential oil) and 10.0 m L/100mL (garlic essentialoil) applied in a mixture containing 1.50 mL/100mL of onion and 0.50 mL/100mL of garlicessential oil were necessary for a complete inhibition of the growth of A. versicolor andsterigmatocystin biosynthesis.The addition of the mixture of caraway and basil extracts (0.35 mL/100mL of caraway + 0.70mL/100mL of basil) to fresh shredded cabbage influenced the reduction of initial mouldcontamination by 93.9%. This was accompanied by the occurrence of acceptable moreintense flavour and slight discoloration.The defined mathematical model for comparing the effects of extracts and essential oils onthe growth of moulds can be applied in establishing inhibition matrices and optimisation ofthe time and the concentration of antifungal agents.The obtained results on the antifungal effects of the spices extracts and onion and garlicessential oils can be beneficial for improving the antifungal protection of food and reducingthe mycotoxin biosynthesis as well as the overall damage caused by the action of moulds.

The aim of this paper was to provide detailed insight into the level of contamination of complete feeding mixtures intended for fattening pigs with mycotoxins-producing fungi and mycotoxins (n = 18). Isolation and enumeration of fungal propagules were done on solid media using the standard microbiological procedure. These plates were incubated, the number of colonies was determined and moulds genera and species identification was carried out using colonies morphological determination and microscopic analysis. Isolates identified as Aspergillus and Penicillium species were subjected to molecular characterization for the presence of genes responsible for the synthesis of OTA (polyketide syntheses gene-PKS). Total fungal counts (CFU/g) ranged from 0,5x105 to 4x106. From a total samples analyzed, seven samples had fungal counts higher than the limit established by Serbian regulations (3x105). During a mycological analysis of complete feeding mixtures intended for fattening pigs, a total of six genera and 14 species of moulds were identified and the most frequent one was genus Penicillium (94,4%). The moulds from genus Fusarium were isolated in 55,5% and Paecilomyces in 44,4% of the samples from investigated localities. Other fungi from the genera Aspergillus (22%), Mycor (11,1%) and Alternaria (5,5%) were represented in a lesser amount. Polymerase chain reaction (PCR) was performed on 18 isolates of the DNA belonging to families Penicillium and Aspergillus. The sequences of PCR reaction products in three samples were compared with nucleotide sequences of genes for polyketide synthase gene (PKS) from Penicillium dance and found that the samples possessed PKS sequence. The traditional methods for identification of ochratoxin-producing fungi are time-consuming and labor-intensive. Rapid and specific detection of ochratoxin-producing fungi is important for ensuring microbiological quality and safety of feed and food. . Radi procene rizika od mikotoksina obavljena su mikološka i mikotoksikološka ispitivanja uzoraka potpunih smeša za ishranu svinja koje potiču iz različitih regiona Srbije (n = 18). Ukupan broj plesni i njihova izolacija u uzorcima potpunih smeša za ishranu svinja, određivan je standardnom mikrobiološkom metodom. Nakon inkubiranja, na osnovu izgleda kolonija i mikroskopske analize obavljena je identifikacija rodova i vrsta plesni. Izolati koji su identifi kovani kao Aspergillus i Penicillium vrste podvrgnuti su molekularnoj karakterizaciji na prisustvo gena odgovornog za sintezu OTA (poliketid sinte taza). Ukupan broj plesni u ispitanim uzorcima bio je od 0,5 × 105 do 4 ×106 (CFU/g). U pogledu ukupnog broja plesni (CFU/g) sedam (38,3 posto) uzoraka bilo je kontaminirano plesnima iznad maksimalno dozvoljene količine (3 × 105). Analizom mikopopulacije uzoraka potpunih smeša za ishranu svinja izolovano je šest rodova i 14 vrsta plesni. Najčešće su izolovane plesni iz roda Penicillium (94,4 posto), zatim Fusarium (55,5 posto) i Paecilomyces (44,4 posto), dok su plesni iz roda Aspergillus (22 posto), Mucor (11,1 posto) i Alternaria (5,5 posto) izolovane u manjem procentu. Lančana reakcija polimeraze (PCR) postavljena je za 18 izolata DNK koje pripadaju rodovima Penicillium i Aspergillus. Sekvence proizvoda PCR reakcije kod tri uzorka poređene su sa nukleotidnim sekvencama gena za poliketid sintetazu (PKS) iz plesni Penicillium i ustanovljeno je da uzorci poseduju PKS sekvencu. Razvoj brzih metoda za determinaciju ohratoksogenih plesni ima za cilj unapređenje sistema kontrole bezbednosti i kvaliteta hrane. U svakoj fazi proizvodnje i prometa hrane može da se spreči, smanji ili eliminiše rizik po krajnjeg korisnika.

Ekološki faktori kao što su temperatura, vlažnost i drugi klimatski faktori u različitim geografskim područjima, imaju uticaj na brzinu rasta i razmnožavanja kvasaca i plesni. Fizičko hemijske osobine mleka utiču na rast kvasaca i plesni, a među najvažnijima su aw, pH, temperatura i druge. Međusobnim uticajem ovih parametara uslovljen je njihov rast i razmnožavanje. Cilj našeg rada bio je da utvrdimo broj kontaminisanih uzoraka sirovog mleka plesnima i kvascima u zavisnosti od godišnjeg doba i geografskog područja. Ecological parametres such as temperature, humidity and other climatic factors in different geographical regions and ecological factors of food production have a complex impact on the speed of growth and multiplication of mould and yeasts. They enable one type of microorganisms to multiply on account of others. Several factors have an impact on the growth of mould and yeasts in raw milk, and the most important ones are as follows: aw, pH and temperature. The interplay between factors ultimately determines grow of yeasts and moulds in raw milk.

Apstrakt je obrađen tehnologijama za optičko prepoznavanje teksta (OCR)Ispitano je prisustvo plesni u začinskim smešama (za proizvodnju mortadele, mesnog nareska, srpske Ijute kobasice, alpske i tirolske salame, viršle i šunkarice), crnom biberu u zrnu i mlevenoj začinskoj paprici. Intenzitet kontaminacije bio je najveći u začinskim smešama (46,13%), zatim crnom biberu (28,95%) i začinskoj paprici (24,92%).Uočena je dominacija grupe kserofilnih plesni iz rodova Aspergillus, Emericella, Eurotium, Paecilomyces, Penicillium i Xeromyces. Konstatovano je da su u začinskim smešama i crnom biberu najbrojniji bili predstavnici rodova Aspergillus i Penicillium, ali su po zastupljenosti u uzorcima (100%) dominirale plesni roda Eurotium {E. herbariorum). U uzorcima začinske paprike najčešće su detektovane plesni roda Rhizopus (R. stolonifer) (87,5%).Od ukupno 45 vrsta identifikovanih tokom mikoloških ispitivanja začina, 55,5% je bilo potencijalno toksigenih. Prisustvo aflatoksina B1 nije konstatovano ni ujednom od začina, ohratoksin A je pronađen kod dva uzorka crnog bibera (u tragovima; 32,00 μg/kg), a zearalenon kod tri uzorka crnog bibera (192,00 do 288,00 μg/kg).Sposobnost sinteze ohratoksina A utvrđena je kod 4 od 5 testiranih sojeva Aspergillus ochraceus (20,00 do 340,00 μg /1). Većina sojeva A. versicolor i 50% E. herbariorum sintetisali su sterigmatocistin u značajnim količinama (100,00 do 1600,00 μg /1, odnosno l60,00 do 400,00 μg /l).A. versicolor se pokazao prilično tolerantnim na uzlaganje visokim temperaturama, preživevši toplotni tretman na 800C (5 i 10 min), ali je narušena fiziološka aktivnost rezultovala smanjenjem proizvodnje sterigmatocistina.Koncentracijom kalijum sorbata od 0,5% u potpunosti je inhibiran rast A. versicolor na čvrstoj hranljivoj podlozi, ali ne i u tečnoj; proizvodnja sterigmatocistina registrovana je samo pri nižim koncentracijama (0,05 i 0,1%)., was processed by technology for Optical character recognition (OCR)The presence of moulds in spice mixtures (for production of mortadella, luncheon meat, "serbian" hot sausage, "alpine" and "tirol" salami, Frankfurter and ham sausage) was investigated. The highest intensity of contamination was in spice mixtures (46,13%), then in black pepper (28,95 %) and in ground red pepper (24,92%).The group of xerophyllic moulds of genera Aspergillus, Emericella, Eurotiiim, Paecilomvces, Penicillium and Xeromyces was dominant. It was found out that the representatives of genera Aspergillus and Penicillium were the most numerous, but considering the incidence in samples (100%) the moulds of genus Eurotium (E. herbariourum) were dominant. In samples of ground red pepper the moulds of the genus Rhizopus (R. stolonifer) (87,5%) were the most frequently detected. Among 45 species identified during mycological investigation of spices, 55,5% were possibly toxicogenic. The presence of aflatoxin B1 was not observed in any of spices tested, ochratoxin A was found in two samples of black pepper (from traces to 32,00 μg/kg), and zaeralenone in three samples of black pepper (192,00 to 288,00 μg/kg).The ability for synthesis of ochratoxin A was observed in 4 of 5 tested strains of Aspergillus ochraceus (20,00 to 340,00 μg/1). The majority of A. versicolor strains and 50% of E. herbariorum synthesized sterigmatocystin in significant quantities (100,00 up to 1600,00 μg/1, and l60,00 up to 400,00 μg/l, respectively).A. versicolor showed to be rather tolerant to exposure to high temperatures by surviving the heat treatment at 800C (5 and 10 min), but the disturbed physiological activity resulted in reduced production of sterigmatocystin.By concentration of potassium sorbate of 0,5% the growth of A. versicolor on solid medium was totally inhibited, but not on liquid medium; the production of sterigmatocystin was registered only at lower concentrations (0,05 and 0,1%).