Search

Lignoceluloza čini glavnu komponentu poljoprivrednog i organskog komunalnog otpada. Zahvaljujući svom sastavu, koji uključuje visok sadržaj šećera, dostupnosti i biorazgradivosti, predstavlja kvalitetnu polaznu sirovinu u biorafinerijskim procesima. Razgradnja kompleksne lignocelulozne strukture je ključni korak u njenoj valorizaciji. Konvencionalne metode za razgradnju lignoceluloze zasnivaju se na upotrebi jakih kiselina i baza i/ili visokih temperatura i pritisaka, čineći ih energetski, ekonomski i ekološki nepovoljnim. Jedan od načina da se ovaj problem prevaziđe je upotreba tzv. „zelenih“ rastvarača, poput vode i etanola. Predmet ovog rada je upotreba zelenih rastvarača u kombinaciji sa gasnom plazmom za razgradnju lignocelulozne biomase pri atmosferskim uslovima. Kukuruzna stabljika je korišćena kao model supstrat, pripremljen sa vodom ili 96% etanolom kao rastvaračima. Za tretman gasnom plazmom korišćena je netermalna gasna plazma igla. Efikasnost primenjenih tretmana praćena je sa aspekta delignifikacije kukuruzne stabljike i naknadne enzimske hidrolize tretirane frakcije. Sadržaj lignina u uzorcima nakon tretmana određivan je na osnovu njegove rastvorljivosti u acetil bromidu (ABSL – acetyl-bromide soluble lignin, engl.). Frakcije dobijene nakon tretmana su podvrgnute enzimskoj hidrolizi sa komercijalnom smešom celulaza, hemicelulaza i ?-galaktozidaza, Cellic CTec 2 (Novozymes, Danska). Nakon 48-časovne hidrolize u dobijenim hidrolizatima je određivan sadržaj heksoza i pentoza. Sadržaj lignina smanjen je za 40% tokom tretmana plazmom u trajanju od 30 minuta u etanolu. U slučaju vode razgrađeno je 20% lignina pri istoj dužini tretmana. Međutim, produžavanjem dužine tretmana na 60 minuta u vodi postignuta je značajna delignifikacija, smanjenjem sadržaja lignina za 50% u odnosu na netretiranu biomasu. Dodatno produžavanje tretmana plazmom na 90 minuta nije dovelo do povećanja stepena delignifikacije. Prinosi šećera ostvareni nakon hidrolize su u skladu sa deli

Lignocellulosic biomass comprises the crop residues, which remain in large quantities from various stages of crop processing. Its main constituents, cellulose, hemicellulose, and lignin, are interlinked by hydrogen and covalent bonds and form a robust and intricate matrix making it resistant to enzymatic degradation. Pretreatment is crucial in lignocellulosic biomass processing, aiming to remove lignin and enhance enzyme access to polysaccharides. This study examines how microwave-assisted peroxide pretreatment affects the delignification of corncobs, aiming to enhance the efficiency of utilizing this agricultural residue in fermentation processes. Taguchi orthogonal array was used to optimize pretreatment conditions and assess the effects of individual parameters (temperature, H2O2 dose, and pretreatment time) on delignification efficiency. The results showed the significant influence of pretreatment conditions on lignin removal from corncobs, with the highest delignification achieved at an H2O2 dose of 500 mg/g, temperature of 100 °C, and pretreatment time of 2 minutes. H2O2 dose had the most substantial impact on the delignification, followed by temperature and pretreatment time. The observed 81.6% delignification and 61.9% increase in cellulose content are pivotal for enzymatic hydrolysis efficiency. This improvement suggests enhanced enzyme availability during hydrolysis and reversible binding to polysaccharide active sites, potentially leading to higher sugar yields., Lignoceluloznu biomasu čine ostaci poljoprivrednih kultura koji u velikim količinama zaostaju na obradivim površinama ili nastaju u različitim fazama njihove prerade. Glavne komponente lignocelulozne biomase (celuloza, hemiceluloza i lignin) su međusobno povezane vodoničnim i kovalentnim vezama stvarajući čvrstu i kompleksnu matricu koja je otporna na dejstvo enzima. Važan korak u procesu prerade lignocelulozne biomase je predtretman kojim je potrebno ukloniti lignin i tako omogućiti lakšu pristupačnost polisaharidnih frakcija enzimima. U ovom radu je ispitivan uticaj peroksidnog predtretmana potpomognutog mikrotalasima na delignifikaciju kukuruznog oklaska sa ciljem dobijanja što čistije polisaharidne frakcije čime bi se omogućila efikasnija valorizacija ovog poljoprivrednog otpada u fermentacionim procesima. Tagučijev ortogonalni niz je korišćen za optimizaciju uslova predtretmana i određivanje uticaja pojedinačnih parametara (temperature, doze H2O2 i vremena predtretmana) na efikasnost delignifikacije. Dodatno, optimalni uslovi su primenjeni u eksperimentu sa konvencionalnim zagrevanjem kako bi se uporedili efekti mikrotalasnog i konvencionalnog predtretmana. Dobijeni rezultati su pokazali da uslovi predtretmana značajno utiču na efikasnost uklanjanja lignina iz kukuruznog oklaska, a najveći stepen delignifikacije je ostvaren pri dozi H2O2 od 500 mg/g, temperaturi od 100 °C i vremenu predtretmana od 2 min. Utvrđeno je da doza H2O2 ima najveći uticaj na proces delignifikacije, a zatim slede temperatura i vreme predtretmana. Delignifikacija od 81.6% i povećanje sadržaja celuloze od 61.9% su značajni za efikasnost enzimske hidrolize u kojoj se može očekivati bolja dostupnost i reverzibilno vezivanje enzima za aktivna mesta na molekulima celuloze i hemiceluloze, a time i bolji prinosi šećera.

The low selectivity of traditional biomass fractionation processes is a major obstacle to the sustainable valorization of agricultural waste in biorefinery processes. The biomass processing has to be accomplished in a way that retains both lignin and polysaccharide fractions which have different properties and potential applications. Although structurally very different, lignin and carbohydrate polymers are closely physically and chemically connected making the lignocellulosic biomass highly recalcitrant to enzyme and microbial degradation. The effective destruction of lignin structure and the breakage of bonds between lignin and hemicellulose or cellulose make the polysaccharide fractions more accessible to enzymes and microbes. To achieve this goal and enable conversion of different biomass fractions into specific products the development of new technologies with fine-tuned process conditions is of utmost importance. In this study, we attempt to intensify lignin removal from corncob and balance it with minimal polysaccharide degradation by coupling microwave irradiation and alkaline peroxide treatment. Taguchi optimization approach was used to select the best set of process parameters and assess each one's contribution to lignin removal and alterations in cellulose surface area. Changes in biomass structure were examined by XRD and FTIR analysis, while the Langmuir adsorption model provided insights into surface phenomena and interactions between hydrolytic enzymes and biomass. Furthermore, the recovered lignin fraction was examined to determine the viability of more sustainable and broader valorisation of biomass in biorefineries. The results of the present study showed that a 1-minute treatment was sufficient to remove 75% of the lignin while increasing the cellulose content and surface area by 57% and 76%, respectively. The fine-tuned process conditions resulted in enhanced adsorption capacity and hydrolysis efficiency of treated biomass, yielding 1.7-fold and

The last decade provided significant advances in the understanding of microbiota and its role in human health. Probiotics are live microorganisms with proven benefits for the host and were mostly studied in the context of gut health, but they can also confer significant benefits for oral health, mainly in the treatment of gingivitis. Postbiotics are cell-free extracts and metabolites of microorganisms which can provide additional preventive and therapeutic value for human health. This opens opportunities for new preventive or therapeutic formulations for oral administration. The microorganisms that colonize the oral cavity, their role in oral health and disease, as well as the probiotics and postbiotics which could have beneficial effects in this complex environment were discussed. The aim of this study was to review, analyse and discuss novel probiotic and postbiotic formulations intended for oral administration that could be of great preventive and therapeutic importance. A special attention has been put on the formulation of the pharmaceutical dosage forms that are expected to provide new benefits for the patients and technological advantages relevant for industry. An adequate dosage form could significantly enhance the efficiency of these products.

Kopriva (Urtica dioica) je samonikla biljka bogata flavonoidima, karotenoidima, fitosterolima, terpenima. Ima izuzetan farmaceutski potencijal zbog svojih antiinflamatornih, antioksidativnih i diuretskih svojstava. Koristi se u ishrani, kao caj ili u formi suvih ili tecnih ekstrakta. U cilju pobiljšanja karakteristika, bioraspoloživosti i stabilnosti ekstrakata, koriste se ekstrakcije ekološki prihvatljivim rastvaracima, zeleni fizicki tretmani i fermentacija probiotickim bakterijama. Zeleni rastvaraci kao što su voda, etanol i biokompatibilni eutekticke tecnosti su pogodni za dobijanje ekstrakata u skladu sa principima održivog razvoja. Inovativni fizicki tretmani kao netermalni tretman plazmom mogu obezbediti bolju ekstrakciju i mikrobiološku stabilnost posebno vodenih ekstrakata. Takode, fermentacije bakterijama, kao što je Ligilactobacillus salivarius, mogu da metabolišu jedinjenja prisutna u ekstraktima i biotransformišu glikozide, tanine i lignane u biološki aktivnije oblike. U radu smo ispitivali rast i antioksidativnu aktivnost vodenih ekstrakata cveta koprive dobijenih uz tretman netermalnom plazmom i potom fermentaciju sa L. salivarius. Ispitali smo rast L. salivarius u medijumima sa razlicitim udelom vodenog ekstrata cveta koprive i Man Rogosa Šarp (MRS) bujona koji je koristi kao standardni mikrobiološki medijum za kultivaciju bakterija mlecne kiseline. Antioksidativna aktivnost dobijenih ekstrakata je ispitana DPPH metodom, pre i nakon fermentacije. L. salivarius je pokazao najbolji rast (11 log CFU/ml) u ekstraktima obogacenim sa 25% MRS. Potom je je ispitivan rast L. salivarius u plazma tretiranom vodenom ekstraktu koprive sa 25% MRS. Nakon tretmana netermalnom plazmom od 3 min i naknadne fermentacije ovih ekstrakata, postignut je rast od 9 log CFU/ml i porast antioksidativne aktivnosti od 27% DPPH metodom. Uocen je pozitivan kombinovani efekat netermalne plazme i fermentacije na povecanje antioksidativne aktivnosti, posebno pri kracim tretmanima nete

Lignocellulosic biomass (LCB) valorization is a fundamental step toward circular bioeconomy. The complex structure of lignocellulose must be disrupted to conduct thorough valorization. Conventional methods often lack sustainability, by having high energy requirements, or a harmful impact on the environment. To overcome these impediments, novel tenable methods must be developed. This work compares different green solvent-based treatments of LCB, regarding the delignification rate and the enzymatic hydrolysis efficiency. Due to abundance and high availability, corn residues were used as model substrates. Deep eutectic solvent (DES), microwave-assisted alkaline treatment, combined non-thermal plasma/Fenton, and non-thermal plasma/alkaline treatment were selected as green methods for LCB treatment, having higher selectivity favoring lignin degradation and milder reaction conditions. Treated biomass was analyzed for acetyl bromide soluble lignin content and subjected to enzymatic hydrolysis with Cellic® CTec2, followed by hexose and pentose content determination. The best results regarding lignin content were obtained with DES, when the choline chloride to lactic acid ratio was 1:10, achieving a delignification rate of 86%. Combined plasma/alkaline treatment for 10 minutes decreased lignin content by 77%, while microwave-assisted alkaline treatment decreased it by 74% for only one minute. When combined with the Fenton reagent, a 30-minute-long plasma treatment reduced lignin content by 53%. Moreover, FTIR spectroscopy confirmed partial depolymerization of lignin, making it more suitable for further application. Each treatment intensified LCB decomposition and facilitated enzyme penetration, increasing hexose yield by 2.3-5.6 times, and pentose yield by 1.7-8.0 times compared to the untreated biomass. Methods implemented in this work contributed to feasible biomass delignification. Coupling alkaline hydrogen peroxide with microwave irradiation or non-thermal plasma or app

To provide food with a longer shelf life, synthetic antioxidants are frequently used in the food industry. Common synthetic antioxidants includebutylated hydroxyanisole(BHA), butylated hydroxytoluene (BHT), propyl gallate (PG), and tert-butylated hydroquinone (TBHQ). Since those compounds are suspected to cause some health problems, such as liver damage, there is a strong initiative to develop and utilizeantioxidantsfrom natural origins.Medicinal plants could be a good alternative source of these compounds. Besides antioxidative properties, natural compounds derived from medicinal plants often have various biological activities, like anti-inflammatory, antimicrobial, analgesic, etc.These compounds can contribute to food's functional and technological properties and interact with food microbiota. In this study, aqueous extracts of tea production residues of common nettle (Urtica dioica L.), St. John’s wort (Hypericum perforatum L.), and hoary willowherb(Epilobium parviflorum L.) were treated with non-thermal plasma. The effect of different durations of plasma treatment on the antioxidative capacity of these extracts was monitored. The fermentation of these extracts solely and extracts supplemented with MRS broth by Ligilactobacillus salivarius was examined. Antioxidative properties of plasma-treated extracts were analyzed using DPPH and ABTS methods. The total phenol content of these extracts was determined by the Folin-Ciocalteu reagent. Generally, hoary willowherb extracts were rich in total phenol content, two or three orders of magnitude richer than the other two plants. They also showed significantly higher antioxidative activity. This activity slightly decreased with prolonged plasma treatment. However, that didn’t affect bacterial growth in these extracts. It was shown that L. salivarius growth was enhanced in the pure plasma-activated extracts of hoary willowherbin comparison to extracts supplemented with MRS broth. Though, the observed effects are substrate

Agro-industry wastes include chemically complex and different substrates, from starch-rich wastes from the conditory industry and bread production to lignocellulose-rich substrates like corn stalks or wheat straw. These substrates could be suitable for fermentation and production of bio-based chemicals by microbial transformations if suitable pretreatment is performed and microorganisms are robust enough to perform biotransformations with high efficacy. Lactic acid bacteria as fastidious microorganisms require optimal C/N ratio in media to grow and produce lactic acid with high yields which presents a challenge when combining different waste substrates which are of varying composition. The presence of undesired components in waste substrates and low pH induced by produced lactic acid cause microbial stress in working microorganisms. Additionally, waste substrates have a complex microbiome and often high moisture content. It is difficult and energy-consuming to stabilise and preserve them for later utilization and open fermentations are a convenient approach. We studied different strategies, both in process engineering and adaptive evolution of microorganisms to achieve higher yields in lactic acid production on these substrates. Possibilities for improvement of lactic acid production included immobilization of microorganisms on organic and inorganic carriers, adaptive evolution for the better valorization of stllages and other substrates and some specific aspects related to the application of cold plasma in the pretreatment of waste substrates for fermentation.

Traditional extraction methods involve the use of polar solvents and/or high temperatures. Both are often energy or time-consuming and require additional purification steps. This compromises the quality of the extracts obtained. Non-thermal plasma pre-treatment for extraction is a promising technique that could increase the sustainability of the process while following the principles of hurdle technology. In this work, we investigated the effects of plasma treatment on the aqueous extraction of antioxidant compounds from herbal tea by-products. Stinging nettle, hoary willowherb, and St. John’s Wort extracts were treated with plasma at different time intervals. The extracts obtained were analyzed for their antioxidant capacity and total phenolic content. Their potential use as growth media for Ligilactobacillus sp. was also investigated. Hoary willowherb extracts showed the highest total phenolic content and antiox-idant activity. While plasma treatment slightly decreased the antioxidant capacity of these extracts, it improved microbial growth. In contrast to hoary willowherb, the antioxidant capacity of stinging nettle extracts’ was not affected by plasma treatment. These extracts were also better for bacterial growth. When added to 25% v/v MRS broth, stinging nettle extracts achieved a growth rate similar to that of pure MRS broth (109 CFU/ml), demonstrating their potential for microbial biomass production and food and feed supplemen-tation., Antioksidansi imaju važnu ulogu u sprečavanju oksidacije masnih kiselina prisutnih u prehrambenim proizvodima, čime značajno produžavaju njihov rok trajanja. Zbog nepovoljnog uticaja pojedinih sintetskih antioksidanasa na zdravlje ljudi, sve je češća upotreba antioksidanasa dobijenih iz prirodnih izvora. Antioksidansi se iz biljnih izvora izoluju ekstrakcijom. Tradicionalne metode ekstrakcije podrazumevaju upotrebu polarnih rastvarača, uz primenu visokih temperatura. Ovi procesi su često energetski nepovoljni, dugo traju i zahtevaju dodatne korake prečišćavanja, kako bi se uklonili toksični rastvarači. Izolovanje biološki aktivnih jedinjenja primenom gasne netermalne plazme kao pretretmana bi moglo da poveća održivost ovog procesa. Osim toga, kombinacijom zelenih rastvarača, poput vode, sa tretmanom plazmom, dobijanje prirodnih antioksidanasa bi bilo u skladu sa tzv. „hardl“ tehnologijom i principima cirkularne ekonomije, kojima se teži u prehrambenoj industriji. Predmet ovog rada je ispitivanje mogućnosti dobijanja prirodnih anti-oksidanasa kombinovanom ekstrakcijom nusproizvoda proizvodnje biljnih čajeva. Vodeni ekstrakti koprive, svilovine i kantariona tre-tirani su plazmom u različitim vremenskim intervalima. Analizirana je antioksidativna aktivnost dobijenih ekstrakata, kao i ukupni sadržaj fenola. Takođe, ispitivana je i mogućnost upotrebe ovih ekstrakata kao fermentacionog medijuma. Najveća antioksidativna aktivnost i najviši sadržaj ukupnih fenola ostvareni su u ekstraktima svilovine. Ove vrednosti su blago opadale sa povećanjem dužine tretmana plazmom, dok je rast bakterija bio poboljšan. Ekstrakti koprive su posedovali značajno manju antioksidativnu aktivnost i niži sadržaj ukupnih fenola od ekstrakata svilovine. Međutim, ovi ekstrakti su bili pogodniji za gajenje bakterija. Dodavanjem 25% MRS bujona u ekstrakte koprive, postignut je približno isti rast Ligilactobacillus salivarius kao u čistom MRS bujonu.

Predloženo tehničko rešenje se odnosi na definisanje procesa u kome se koristi sporedni proizvod industrije piva i dobija novi proizvod obogaćen probiotskom biomasom koji je namenjen ishrani preživara. Tehnološki postupak podrazumeva primenu pivskog tropa kao nosača za imobilizaciju bakterija mlečne kiseline. Soj Lactobacillus paracasei NRRL B-4564 je imobilisan na površinu pivskog tropa, a dobijeni imobilizat je potom korišćen u mlečno-kiselinskoj fermentaciji sa recirkulacijom imobilisane mikrobne biomase u više uzastopnih 18 šaržnih ciklusa. Primenom kontrolisanog procesa dobijen je fermentisani pivski trop koji predstavlja proizvod boljeg nutritivnog kvaliteta (većeg sadržaja proteina i pepela, manjeg sadržaja svih frakcija vlakana), veće energetske vrednosti i bolje svarljivosti u odnosu na polaznu sirovinu. Pored boljih parametara kvaliteta, dobijeni fermentisani proizvod je obogaćen visokom koncentracijom vijabilne probiotske biomase Lactobacillus paracasei NRRL B-4564. Primenom opisanog tehnološkog postupka je omogućeno stvaranje dodatne vrednosti sporednog proizvoda industrije piva.

Biomass captures CO2 from the atmosphere when growing. In the same time, approximately 1,4 Gt of available renewable biomass is annually wasted while cereal straw wastes contribute to that with 66%. Huge portion of residues is still burnt, while it is the source of bioactives, fermentable sugars and only natural aromatic polymer-lignin. The main obstacle for valorization of biomass is the recalcitrant nature of dominantly present lignocellulose and variability in biomass composition which decreases already modest efficiency of acid/alkaline thermal treatment conventionally used in biorefineries. Conventional treatments have low selectivity, generate inhibitory compounds for enzymes or microorganisms used in biorefineries and have high environmental footprint. Cold plasma treatment (CPT) can induce modifications of cellulosic and hemicellulosic fraction as well as oxidation and depolymerisation of lignin, but CPT lacks selectivity in complex substrates such as agri-food wastes. We combined CPT with Fenton reagent or hydrogen peroxide for treatment of corn stalks as significant lignocellulose agri-industrial waste in Serbia. Chemical properties of treated samples were analysed by FTIR, while carbohydrate fraction was subjected to enzymatic hydrolysis followed by spectrophotometric analysis. We showed that delignification with CPT can be efficiently combined with other oxidative treatments, including hydrogen peroxide and Fenton reagent, while preserving or even improving the enzymatic hydrolysis of carbohydrate fractions. Different chemical modifications were obtained depending on Fe/hydrogen peroxide ratio or hydrogen peroxide concentration, however, low energy CPT combined with other oxidative treatments significantly improves delignification and carbohydrate accessibility while decreasing overall processing time and energy consumption. Further studies have to evaluate oxidative treatments and CPT sources with different parameters for recovery of all fractions prese, Biljna biomasa vezuje CO2 iz atmosphere kada raste. U isto vreme, otprilike 1,4 Gt dostupne obnovljive biomase se godišnje baca, dok slama žitarica koja se smatra otpadom učestvuje sa oko 66% u toj količini. Veliki deo agroindustrijskog otpada se i dalje spaljuje, dok je istovremeno izvor bioaktivnih jedinjenja, fermentativnih šećera i jedinog prirodnog aromatičnog polimera –lignina. Osnovno ograničenje u valorizaciji biomase predstavlja rezistentnost lignoceluloze, dominantne frakcije u većini sporednih sirovina agroindustrijskog porekla, kao i varijabilnost sastava. Time se dodatno smanjuje i onako ogranična efikasnost kiselinskih/baznih termalnih tretmana koji se konvencionalno koriste u biorafinerijskim postupcima. Konvencionalni tretmani imaju malu selektivnost, u njima nastaju inhibitorni proizvodi za enzime i mikroorganizme koje se koriste u biorafinerijskim postupcima i imaju značajan uticaj na životnu sredinu. Tretman hladnom plazmom (THP) može izazvati modifikacije na celuloznoj i hemiceluloznoj frakciji, kao i oksidaciju i depolimerizaciju lignin, ali THP nedostaje selektivnost u kompleksnim supstratima kao što je agro-industrijski otpad. Mi smo kombinovali THP sa Fentonovim reagensom ili vodonik peroksidom u tretmanu kukuruznih stabljika kao značajnog izvora lignoceluloze agroindustrijskog porekla u Srbiji. Hemijska svojstva tretiranih uzoraka su analizirana FTIR-om, dok je ugljenohidratna frakcija bila podvrgnuta enzimskoj hidrolizi i analizirana spektrofotometrijskim metodama. Pokazali smo da delignifikacija THP može da se efikasno kombinuje sa vodonik peroksidom i Fentonovim reagensom tako da se očuva ugljenohidratna frakcija pogodna za enzimsku hidrolizu. Dobijene su razlike u hemijskim modifikacijama u zavisnosti od primenjenog odnosa Fe/vodonik peroksid ili koncentracije vodonik peroksida. Utvrđeno je da THP može biti kombinovan sa drugim naprednim oksidativnim procesima i značajno unaprediti delignifikaciju i dostupnost ugljenih hidrata, uz smanje

Lactic acid bacteria have an important role in food production, as probiotics and producers of lactic acid. Due to the generation of oxygen and nitrogen-based reactive species and UV radiation, non-thermal plasma (NTP) was found to be effective in microbial inactivation and food processing. In this study, we investigated the effect of atmospheric NTP on Lacticaseibacillus paracasei NRRL B-4564 survival, membrane alternations, and the response of treated cells to acidic stress. Cell suspensions in water were subjected to different treatment time intervals using a custom-made plasma needle. Argon was used as a feed gas, with a flow of 0.5 slm, while the distance between the needle tip and suspension surface was 1.5 cm. Immediately after the treatment, the viable cell number was estimated by the pour plate method, while cell membrane alternations were studied by analyzing zeta potential and membrane permeability (Crystal Violet assay). To ascertain if sub-lethal NTP stress could influence L. paracasei survival in an acidic environment, NTP-treated cells were challenged by pH 2.5 for 3h. The results demonstrate that the negative surface potential of the bacterial membrane (-29.83±1.49 mV for untreated) was gradually shifted towards neutrality (-7.59±0.54 mV after 180 s) with prolonged treatment time. Increasing cell exposure to NTP resulted in higher membrane permeability, which was correlated with viable cell reduction. The cells exposed to shorter treatment time (30 and 60 s) kept viability and showed better survival in low pH compared to untreated cells, suggesting the application of NTP in probiotic food processing.

During the processing of herbs, a significant amount of chopped biomass by-products is left behind, often discarded and underutilized. Since they are important sources of different groups of bioactives like polyphenolics, essential oils or terpenes and structural compounds like lignocellulose, they could be exploited in fermentation by different microorganisms. However, fractionation and extractions could significantly increase the effectiveness and productivity of the valorization process. We examined the possibility of extracting antioxidants from by-products of hoary willowherb (Epilobium spp.), sage (Salvia spp.), and basil (Ocimum spp.), as medicinal herbs with significant pharmaceutical and market value. Extracts of hoary willowherb, sage and basil residues were obtained by a conventional, Soxhlet extraction for polar compounds and supercritical carbon(IV)-oxide extraction as an unconventional extraction method for non-polar compounds. We measured the antioxidant content in the obtained extracts by the ABTS and DPPH spectrophotometric methods. In addition, we measured the total polyphenol content of the extracts by the Folin-Coicalteu method. According to the ABTS method, the antioxidant activity in the sage extracts obtained from Soxhlet extraction is 2.2 times greater than in the extracts obtained from supercritical carbon(IV)-oxide extraction. The antioxidant activity in the basil extracts obtained from Soxhlet extraction is 9.1 times greater than in the extracts obtained from supercritical carbon(IV)-oxide extraction, according to the DPPH method. The total polyphenol content in the hoary willowherb extracts obtained from Soxhlet extraction is 4.6 times greater than in the extracts obtained from supercritical carbon(IV)-oxide extraction. The antioxidant activity is greater in the extracts obtained by Soxhlet extraction than in the extracts obtained with supercritical carbon(IV)-oxide extraction. Because we examined residues from the tea processing industry

Corn is one of the world´s most commonly cultivated crops.A major part of the plant remaining after harvesting is the corn stalk.This corn residueis rich in carbohydrates and could be suitable for the fermentative production of numerous value-added products. The corn stalk’s complex structure, recalcitrance deriving from lignin, and high crystallinity and polymerization degree of cellulose prevent conventional pretreatment techniques to separate it efficiently into elementary fractions. Therefore, it is usually processed by burning directly on the ground or landfilling.It seldom can be used for composting or combusted for heat generation. In this study, different advanced oxidation processes were used for the treatment of corn stalks to enable more sustainable valorization of biomass by enzymatic hydrolysis. The effects of non-thermal plasma treatment, treatment with Fenton reagent, and combined non-thermal plasma/Fenton treatment on lignocellulose degradation and biomass digestibility were monitored. Treatment efficacy in terms of degradation was assessed by determininglignincontent. Structural and textural properties of treated biomass were analyzed using FTIR analysis and mercury intrusion porosimetry (MIP).The carbohydrate digestibility estimation was based on hexose and pentose content in hydrolyzed samples. Applied treatments showed success in breaking complex lignocellulose structures. The delignification rates for the non-thermal plasma treated sample, thesample treated only with the Fenton reagent, and the combined non-thermal plasma/Fenton treated sample were 19%, 28.7%, and 53%, respectively. Selectivity towards lignin increased with prolonging the non-thermal plasma treatmentorthe addition of the Fenton reagent.To achieve a delignification rateof 53% by using only non-thermal plasma, treatment should last at least 60 minutes. When the Fenton reagent is added, the same result is obtained with a halved duration of the plasma treatment. Under these conditio

Najveći deo ćelijskog zida viših biljaka se sastoji od tri polimerna molekula, celuloze, hemiceluloze i lignina. Imajući u vidu zastupljenost ova tri polimera u prirodi, lignocelulozna biomasa se danas smatra važnom sirovinom za proizvodnju biogoriva i biohemikalija. U navedenim procesima prvi i najvažniji korak je narušavanje složene strukture lignocelulozne biomase i oslobađanje polisaharidnih frakcija, čime se biomasa priprema za hidrolizu do prostih šećera. Cilj ovog rada bio je ispitati na koji način oksidativni tretman primenom vodonik peroksida u alkalnim uslovima utiče na karakteristike ćelijskog zida kukuruzne biomase i da li nastale promene u sastavu i strukturi tretirane biomase dovode do efikasnije enzimske hidrolize. Kukuruzna biomasa je tretirana alkalnim rastvorom vodonik peroksida u mikrotalasnoj pećnici u trajanju od 60 s i pri snazi od 360 W. Nakon ispiranja i sušenja, uzorci su podvrgnuti enzimskoj hidrolizi pomoću enzima Cellic® CTec2, kao i odgovarajućim analitičkim metodama za određivanje dostupnosti celuloze, kapaciteta adsorpcije enzima, indeksa kristaliničnosti i stepena delignifikacije. Efikasnost hidrolize tretirane i netretirane biomase je utvrđena merenjem koncentracije redukujućih šećera u dobijenim hidrolizatima. Dostupnost celuloze je ispitivana na osnovu adsorpcije boje Kongo crveno i izračunavanjem površine celuloze fitovanjem eksperimentalno dobijenih podataka sa jednačinom Lengmirove adsorpcione izoterme. Indeks kristaliničnosti je određen na osnovu vrednosti jodnog broja, a stepen delignifikacije acetil-bromid metodom. Takođe, ispitivanjem adsorpcije enzima Cellic® CTec2 i na osnovu konstanti Lengmirove adsorpcione izoterme utvrđen je maksimalni kapacitet adsorpcije enzima. Dobijeni rezultati su pokazali da vodonik peroksid pri ispitivanim uslovima prvenstveno reaguje sa ligninom. Udeo lignina u tretiranoj biomasi je bio za 70% manji u odnosu na netretirani uzorak. Usled smanjenja sadržaja lignina površina celuloze tretirane biom

Lignocellulosic biomass is a cheap raw material that, thanks to its high carbohydrate content, can be used in fermentation to produce biofuels, biogas and other compounds. Its complex structure, including cellulose, hemicellulose and lignin, requires prior treatment of the biomass to facilitate hydrolysis to simple sugars. Today, biomass is only partially utilized and generates about 14% of the world ́s energy. This is because the most commonly used physical, chemical and physicochemical treatments are not sustainable. They are energy-consuming but still low in productivity and toxic inhibitors formed during these treatments could hinder later steps of fermentation. Biomass treatment with advanced oxidation techniques has great potential as an environmentally friendly, so-called "green" treatment. These processes generate reactive species (radicals, electrons, ions and peroxides) that attack cellulose, hemicellulose, and lignin components. In this work, the effects of non-thermal plasma, the Fenton process, and the combined treatment of corn stalks with non-thermal plasma/Fenton were compared. Grounded biomass of corn stalks was mixed with Fenton reagent and hydrogen peroxide at different ratios and subjected to non-thermal plasma treatment. Carbohydrate content was decreased in non-thermal plasma treated samples both with and without Fe2+. However, a specific biomass: Fe2+:H2O2 ratio was required to achieve the highest rate of lignocellulose decomposition. The cellulose and hemicellulose fractions were affected and reduced by the treatments studied but resulted in almost no changes in the cellulose crystallinity index. The lower lignin content and cellulose crystallinity allow for more efficient enzyme hydrolysis of the treated lignocellulose and new options for valorization in fermentations., Lignocelulozna biomasa predstavlja jeftinu sirovinu koja se može koristiti u fermentacionim procesima za dobijanje biogoriva, biogasa i drugih jedinjenja, zahvaljujući visokom sadržaju ugljenih hidrata. Složena struktura, koja uključuje celulozu, hemicelulozu i lignin, zahteva prethodni tretman biomase kojim se olakšava hidroliza do prostih šećera. Danas se biomasa samo delimično eksploatiše i generiše oko 14% energije na svetskom nivou. To je prevashodno zbog male održivosti najčešće korišćenih fizičkih, hemijskih i fizičko-hemijskih tretmana. Ovi procesi troše veliku količinu energije, imaju malu produktivnost, a toksični sporedni proizvodi koji nastaju tokom tretmana mogu ometati kasnije korake fermentacije. Tretman biomase naprednim oksidacionim procesima ima veliki potencijal kao ekološki prihvatljiv, tzv. „zeleni“ tretman. Tokom ovog procesa dolazi do stvaranja reaktivnih vrsta (radikala, elektrona, jona i peroksida), koje napadaju celulozu, hemicelulozu i lignin. U ovom radu upoređeni su efekti tretmana kukuruzne stabljike netermalnom plazmom, Fentonovim reagensom i kombinovanog tretmana netermalnom plazmom/Fentonreagensom.Samlevena biomasa kukuruzne stabljike pomešana je sa Fentonovim reagensom i vodonik peroksidom u različitim odnosima, a zatim je podvrgnuta tretmanu netermalnom plazmom. Sadržaj celuloze i hemiceluloze je značajno smanjen u uzorcima tretiranim netermalnom plazmom i u prisustvu i u odsustvu Fe2+. Ipak, najveći stepen redukcije lignoceluloze je postignut pri određenom odnosu biomasa:Fe2+:vodonik peroksid. Primenjeni tretmani su uticali i na hemiceluloznu frakciju, ostavljajući indeks kristaliničnosti celuloze skoro nepromenjenim. Niži sadržaj lignina i manji indeks kristaliničnosti celuloze omogućavaju efikasniju enzimsku hidrolizu tretirane lignoceluloze i nove načine za valorizaciju u fermentacionim procesima.

Food waste and by-products are generated in all stages of food supply chain and it is estimated that third of all produced food is wasted. The goal is to minimise avoidable waste, to recover resources in sustainable way and to recycle them back into the food chain. A bibliometric mapping is used to analyse state of the art in non-thermal processing of food waste and by-products. Maximizing product yield, lowering energy consumption, economical, and environmental aspects are essential criteria for designing a new sustainable biorefinery process on food wastes and by-products. Many compounds important for food industry could be recovered or produced by non-thermal processing and bioprocessing: organic acids, antioxidants, aromas, sugars, fibres, proteins etc. These are the emerging technologies to increase the conversion efficiency, to decrease generation of toxic compounds, and to reduce microbial load of substrates. The selected cases of cascade and integrated processes were discussed, with examples focused on substrates, roles of non-thermal processing and bioprocessing in lactic acid production.

Common nettle (Urtica dioica) is widely spread medicinal plant growing in Europe. It is used as food, herbal tea or extract in dietary supplements. Significant amount of common nettle herb residues remains during standard herb processing in herbal tea production – due to grounding and fragility of dried common nettle’s leaf. These residues are currently underexploited and are considered waste, but could be used for extraction. Dried or liquid extracts of pharmacopoeial-level quality common nettle are used in iron supplementation, in treatments of rheumatoid diseases, hyperthensia or hyperglycemic disorders. Green solvents, water and ethanol are preferable for sustainable extractions and food and health related applications. Additionally, these solvents favour extraction of polar compounds like glycosides which could be metabolized by microorganisms. Water extracts do not harm microorganisms and are used as such in fermentation while ethanol have to be removed before fermentations. In our work, we studied water extraction of common nettle herb and its residues and tested these extracts as substrates for the growth of Ligilactobacillus salivarius and Lacticaseibacillus rhamnosus, bacteria with probiotic potential. Antioxidant activity (DPPH and ABTS methods) and growth of L. salivarius and L. rhamnosus were common nettle’s extracts obtained under different conditions. The extracts obtained from residues showed comparable or even superior antioxidant activity to extracts obtained from standard herb. Common nettle extracts without carbon or nitrogen supplementation were poor substrates for the growth of L. salivarius and L. rhamnosus, while supplementation with broth in low percentages resulted in growth stimulation above control. Findings suggest that common nettle herb residues could be valorised in food chain avoiding landfill disposal and wasting of this valuable resource., Kopriva (Urtica dioica) je široko rasprostranjena biljka koja raste širom Evrope. Koristi se za ishranu, kao čaj ili u formi ekstrakta u dijetetskim suplementima. Tokom prerade herbe koprive i pakovanja za primenu u formi čajeva nastaje značajna količina otpada – izdrobljene herbe koprive. Ovaj otpad se za sada ne koristi i smatra se otpadom, ali bi se mogao koristiti za ekstrakcije. Suvi i tečni ekstrakti koprive farmakopejskog kvaliteta se koriste za tretmanu anemija, reumatoidnih bolesti, hipertenzije i hiperglikemijskih poremećaja. Zeleni rastvarači, voda i etanol su najpogodniji za dobijanje ekstrakata na održiv način za prehrambene i farmaceutske primene. Takođe, ovi rastvarači pogoduju ekstrakciji polarnih jedinjenja kao što su glikozidi koje mogu da fermentišu mikroorganizmi. Vodeni ekstrakti se mogu koristiti bez tretmana, jer ne utiču negativno na rast mikroorganizama, dok je iz etanolnih ekstrakata neophodno ukloniti etanol pre fermentacije. U radu smo proučavali vodenu ekstrakciju herbe koprive i otpada dobijenog preradom herbe. Testirali smo ekstrakte kao supstrate za rast Ligilactobacillus salivarius i Lacticaseibacillus rhamnosus, bakterija sa probiotskim potencijalom i antioksidantnu aktivnost ekstrakata (DPPH i ABTS metode). Antioksidantna aktivnost i rast L. salivarius i L. rhamnosus su ispitivani u ektraktima koprive dobijenim pod različitim uslovima. Ekstrakti dobijeni iz otpadna herbe koprive su pokazali sličnu ili čak bolju antioksidativnu aktivnost u odnosu na ekstrakte standardno korišćene herbe. Ekstrakti koprive bez dopune izvorima ugljenika ili azota su bili loš supstrat za rast L. salivarius i L. rhamnosus, dok su ekstrakti obogaćeni bujonom u niskom procentu pokazali rast bolji od kontrolnog uzorka. Rezultati rada ukazuju na potencijal otpada iz prerade koprive za primenu u prehrambenoj industriji čime bi se izbeglo odlaganje na deponije i bacanje ovog vrednog resursa.

Introduction Agricultural residues are abundant and cheap sources of lignocellulose widely available but with varying composition which strongly affects valorization routes. Valorization of agricultural biomass into bio-based chemicals is usually oriented towards treatments to release fermentable sugars from complex and strongly bonded molecules of cellulose, hemicellulose and lignin within lignocellulose. Treatments of lignocellulose were mostly studied to make it accessible to cellulases for hydrolisis of carbohydrates which could be then fermented into organic acid by lactic acid bacteria or bioetahnol by Saccharomyces sp., for example. In these processes valorization of lignin fraction was often neglected. However, lignin is among the most abundant aromatic polymers on planet with estimated amounts of over 300 billion tons and with annual increments estimated by around 20 billion tons (Smolarski, 2012). Lignin could be a raw material for numerous currently petrol-based chemicals like additives, thermoplastics and compounds used in pharmaceutical industry (Ponnusamy et al., 2019). Material and methods We studied the effects of advanced oxidation techniques, namely Fenton process, non-thermal plasma treatment and combination of these treatments on degradation of corn stalks as agroindustry based lignocellulosic substrate. Chemical composition was studied using FTIR, bioaccessibility and acetyl bromide soluble lignin content were determined by spectrophotometric methods while morphology of samples was examined by SEM. Different concentrations of Fe2+/Fe3+ and H2O2 were added to the grounded biomass of dried corn stalks and subjected to the plasma treatment. Results and Discussion The results showed that Fe/H2O2 ratio strongly affects degradation outcomes, where 1:5 Fe/H2O2 affects more carbohydrate fraction of substrate, while higher ratios are needed to affect significantly lignin fraction. The effect is potentiated with additional plasma treatment. These results

Lignocellulosic biomass has become one of the most explored renewable substrates for the production of many valuable chemicals, biofuels, and food or feed ingredients or products. However, a complex structure blocs its direct utilization and directs to utilization of particular pretreatments in order to remove lignin and facilitate the biomass hydrolysis prior to its further processing. The pretreatments could be done by chemical, physical, physicochemical means, or using biological methods. Biological methods involving the use of fungi or their enzymes in the pretreatment and hydrolysis of the lignocellulosic substrate are ecologically friendly, rather time consuming, but with no formation of harmless components that can inhibit the production microorganism (Nair and Sivakumar, 2020). The limitations, such as process longevity and loss of valuable sugars, can be alleviated or overcome by utilization of novel efficient microorganisms, e.g. fungi which are selective biomass decomposers, as well as by optimizing conditions of the pretreatment. In this study, a potential use of novel isolated Serbian autochthonous fungi in the pretreatment of lignocellulosic biomass was studied. Isolates were collected in the southern Serbia near the City of Leskovac. The strains were isolated from stumps, fallen trees and branches, fallen leaves, or living trees found in the oak forest and orchards around the forest. Among 12 isolated fungi, the isolates identified as Trametes hirsuta F13 and Stereum gausapatum F28 stood out as ligninolytic enzyme producers and were selected for potential use in the pretreatment of waste lignocellulosic biomass (beechwood sawdust). Table 1. shows biomass and lignin reduction and selectivity coefficients relative to the total lignin reduction (selectivity coefficient 1), and relative to the Klason’s lignin reduction (selectivity coefficient 2) after 35 days of incubation under non optimized conditions. More lignin was degraded by T. hirsuta F13 than S.