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Fenolni spojevi su poželjan sastojak vina zbog njihovog dobro poznatog pozitivnog učinka na zdravlje ljudi, međutim zbog podložnosti oksidaciji, mogu negativno utjecati na boju, stabilnost te ukupnu kvalitetu bijelih vina. Sumporni dioksid, učinkovit antioksidans koji se koristi za stabilizaciju i sprječavanje posmeđivanja, izbjegava se zbog mogućeg štetnog utjecaja na zdravlje ljudi i kvalitetu vina. Stoga se koriste i istražuju druga sredstva kao npr. polivinilpolipirolidon (PVPP) i lakaza. PVPP je sintetski polimer koji veže fenolne spojeve i time sprječava njihovu oksidaciju. Nasuprot tome, enzim lakaza katalizira oksidaciju fenolnih spojeva te ubrzava nastajanje visokomolekularnih smeđe obojenih polimera koji se uklanjaju odgovarajućim postupcima filtracije vina. Na taj način se sprječava naknadna oksidacija fenolnih spojeva te posmeđivanje i zamućenje vina. S tim u vezi cilj istraživanja bio je ispitati utjecaj tretmana PVPP-om ili lakazom na fizikalno-kemijska svojstva (udjeli etanola, ukupnog ekstrakta, hlapljivih i nehlapljivih kiselina, pH-vrijednost, intenzitet boje), senzorsku kvalitetu i koncentraciju pojedinih skupina fenolnih spojeva (flavonoidi, neflavonoidi, kondenzirani tanini, leukoantocijani) bijelog vina Laški rizling. Finalizacija netretiranog (kontrolnog) vina i vina tretiranih PVPP-om odnosno lakazom provedena je ultrafiltracijom. Odabrani uvjeti tretmana, provjereni su brzim testiranjem u laboratorijskim uvjetima: aroma je u vinu ostala nepromijenjena, a masena koncentracija koloida je smanjena. Stoga su isti uvjeti tretmana primijenjeni u industrijskom mjerilu te uglavnom nisu značajno utjecali na fizikalno-kemijska svojstva, a poboljšali su senzorsku kvalitetu tretiranih vina. Smanjili su koncentracije svih skupina fenolnih spojeva i rezultirali manjim intenzitetom boje tj. svjetlijom bojom tretiranih od kontrolnog vina. Dobiveni rezultati ukazuju na prikladnost PVPP-a i lakaze u postupcima očuvanja boje i kvalitete bijelog vina Laški rizling., Phenolic compounds, with their well known positive effect on human health, are a desirable constituent of wine, however, due to their susceptibility to oxidation, they can negatively affect the color, stability and overall quality of white wines. Sulphur dioxide, the effective antioxidant used for wine browning prevention and stabilization, is avoided cause of possible harmful effect on human health and wine quality. Therefore, other agents such as polyvinylpolypyrrolidone (PVPP) and laccase are used, and investigated as well still , too. PVPP ( a synthetic polymer) binds phenolic compounds and thus prevents their oxidation. In contrast, the enzyme lacase catalyzes the oxidation of phenolic compounds and accelerates the formation of high molecular weight brown polymers which are removed in finalization processes such as ultrafiltration. In this way, the subsequent oxidation of phenolic compounds as well as wine browning and turbidity are prevented. Considering the above facts, the aim of this study was to examine the effectiveness of treatment with PVPP or laccase, combined with ultrafiltration, on the physicochemical properties (contents of ethanol, total extract, volatile and non-volatile acids, pH value, color intensity), sensory quality and the concentration of individual groups of phenolic compounds (flavonoids, neflavonoids, condensed tannins, leukoanthocyanidins) of Laški Riesling white wine. Finalization of untreated (control) wine and wines treated with PVPP or laccase and treated wines was performed by ultrafiltration. The selected experimental conditions were previously tested in laboratory scale and confirmed that colloid content was reduced by treatments with PVPP or laccase. while wine aroma was not significantly impaired. Further, the same treatments were applied in the industrial conditions and according to obtained results they did not significantly affect the basic physicochemical properties, but improved the sensory quality of the treated wines. Therefore, the same treatment conditions were applied in industrial scale and generally did not significantly affect the physico-chemical properties, while the sensory quality of the treated wines were improved. The concentrations of all groups of phenolic compounds and color intensities were reduced in the treated wines when compared to color control wine. The obtained results indicate the suitability of both PVPP and laccase in the processes of stabilization and color preservation of white wine Laški Riesling.

The δ18O and δ13C (analyzed by isotope ratio mass spectrometry, IRMS) and concentration of 22 selected elements (analyzed by inductively coupled plasma—optical emission spectrometry, ICP-OES) in 190 Croatian microvinified and commercial wine samples from continental and coastal winegrowing areas and from three viticultural zones (B, CI, and CII) were measured to investigate whether multivariate statistical methods could provide the fingerprint for geographical origin determination. The highest power for discrimination of wines produced in Croatian winegrowing areas was achieved by general discriminant analysis (GDA) showing correct classification of 97.9% of all investigated samples, 100.0% of microvinified samples and 84.8% of commercial samples in the cross-validation matrix. The most significant markers for discrimination of coastal and continental areas found by GDA were δ18O and Co, followed by K, Rb, Sn, Li, and δ13C in descending order. GDA showed higher levels of correctly classified samples from three viticultural zones in Croatia if only microvinified samples were employed in the analysis (94.9%) than for all samples together (86.3%) or for commercial samples (66.1%) in the cross-validation matrix. The discrimination of viticultural zones B, CI, and CII in Croatia was achieved by δ18O, Co, Rb, Li, K, and Sn. The results obtained showed that the relationships between the isotopic ratios and concentrations of different considered elements combined with appropriate statistical model represent a powerful tool in discrimination of wines produced in different Croatian winegrowing areas.

The objective of this study was to evaluate the potential of green solvents for extractions of bioactive compounds (BACs) and essential oils from wild thyme (Thymus serpyllum L.) using theoretical and experimental procedures. Theoretical prediction was assessed by Hansen solubility parameters (HSPs) and conductor-like screening model for realistic solvents (COSMO-RS), to predict the most suitable solvents for extraction of BACs. An experimental procedure was performed by nonthermal technology high voltage electrical discharge (HVED) and it was compared with modified conventional extraction (CE). Obtained extracts were analyzed for chemical and physical changes during the treatment. Theoretical results for solution of BACs in ethanol and water, as green solvents, were confirmed by experimental results, while more accurate data was given by COSMO-RS assessment than HSPs. Results confirmed high potential of HVED for extraction of BACs and volatile compounds from wild thyme, in average, 2.03 times higher yield of extraction in terms of total phenolic content was found compared to CE. The main phenolic compound found in wild thyme extracts was rosmarinic acid, while the predominant volatile compound was carvacrol. Obtained extracts are considered safe and high-quality source reach in BACs that could be further used in functional food production.

The aim of this study was to evaluate the impact of the macerating enzyme addition (Sihazym Extro and Vinozym Vintage) on the extraction of phenolics, colour components, and antioxidants in Babica wine. Spectrophotometry was used for determination of total phenolics, anthocyanins, and wine colour parameters (intensity, hue, and chromatic structure); the individual phenolics were detected using HPLC; while reducing and free radical scavenging activities of the samples were analysed using the FRAP and DPPH assays. The results indicate a more favourable effect of the Sihazym Extro on the extraction of phenolics, while both enzymes improved the extraction of anthocyanins during the maceration. The most abundant phenolic compounds were malvidin derivatives whose concentration continuously increased during the vinification and reached 82% of all anthocyanin derivatives in the control wine and 81% in both enzyme-treated wines. As expected, the antioxidant activity of the samples followed the trend of phenolics content growth and increased during the vinification, resulting in the higher activity of the enzyme-treated wines.

Food safety is one of the main concerns in the world and in wine it depends mostly on metabolites of microbial origin. The aim of this study was to investigate the occurrence of natural contaminants, ochratoxin A and biogenic amines (cadaverine, histamine, putrescine and tyramine), in Croatian commercial red wines originating from different Croatian wine-making regions. Ochratoxin A was detected in 92.8% of samples, however its concentrations in all samples were more than 10-fold lower than the limit set by the European Union (2 &micro, g/kg), marking these wines as safe for consumption. The frequency of occurrence and measured concentrations of ochratoxin A were higher in wines produced in southern regions with highest values obtained in wines from southern Dalmatian islands. All samples were contaminated with cadaverine and putrescine, while 88.2% and 82.7% were contaminated with histamine and tyramine, respectively. Histamine concentrations ranged from below the limit of detection to 8.5 mg/L. Higher histamine concentrations were measured in wines with higher pH values which coincided with southern geographic origin. These results reinforce the need for routine detection and quantification of biogenic amines in Croatian wines to achieve better control of vinification and minimize their formation.

Crljenak kaštelanski or Tribidrag is a Croatian autochthonous grape variety which is a parent of the America’s most popular variety Zinfandel or Italian Primitivo. The aim of this study was to investigate the dynamics of extraction of phenolics and changes in antioxidant activity of the samples collected during maceration of C. kaštelanski grapes processed using two different macerating enzymes. According to the obtained results it can be concluded that wines from C. kaštelanski grapes are great source of bioactive phenolics although differences in phenolic profiles between control and enzyme-treated wines were detected. The highest content of total phenolics was detected in control wine (2691 mg GAE/L). Use of pectolitic enzyme Vinozym Vintage improved anthocyanin extraction, while higher colour parameters were observed for wine samples produced using Sihazym Extro. The statistical analysis confirmed great influence of total phenolics and concentrations of some individual phenolic compounds (e.g. catechin, gallic acid, epicatechin) on reducing and free radical scavenging activity of wine samples while the impact of anthocyanins was not detected. According to the obtained results it can be concluded that use of enzymes has slightly negative effect on total phenolics and wine antioxidant properties, but it increases the extraction yield of wine colour components what enables shorter maceration and prevents colour losses during the aging process.

Crljenak kastelanski or Tribidrag is a Croatian autochthonous grape variety which is a parent of the America’s most popular variety Zinfandel or Italian Primitivo. The aim of this study was to investigate the dynamics of extraction of phenolics and changes in antioxidant activity of the samples collected during maceration of C. kastelanski grapes processed using two different macerating enzymes. According to the obtained results it can be concluded that wines from C. kastelanski grapes are great source of bioactive phenolics although differences in phenolic profiles between control and enzyme-treated wines were detected. The highest content of total phenolics was detected in control wine (2691 mg GAE/L). Use of pectolitic enzyme Vinozym Vintage improved anthocyanin extraction, while higher colour parameters were observed for wine samples produced using Sihazym Extro. The statistical analysis confirmed great influence of total phenolics and concentrations of some individual phenolic compounds (e.g. catechin, gallic acid, epicatechin) on reducing and free radical scavenging activity of wine samples while the impact of anthocyanins was not detected. According to the obtained results it can be concluded that use of enzymes has slightly negative effect on total phenolics and wine antioxidant properties, but it increases the extraction yield of wine colour components what enables shorter maceration and prevents colour losses during the aging process.

Osiguranje kvalitete temeljni je čimbenik u dobivanju pouzdanih, vjerodostojnih i ponovljivih rezultata analiza. Cilj rada je prikazati način kontrole kvalitete rezultata ispitivanja vina, a time i osposobljenost laboratorija, provedbom unutarnje i vanjske kontrole kvalitete za četiri odabrana parametra: relativna gustoća, alkoholna jakost, hlapljiva i ukupna kiselost. Unutarnja kontrola kvalitete provedena je primjenom kontrolnih karata za interni referentni materijal, a vanjska kontrola kvalitete sudjelovanjem u međulaboratorijskim usporedbenim ispitivanjima. Prikazane su vrijednosti statističke obrade rezultata laboratorija na osnovu kojih se procjenjuje uspješnost sudjelovanja laboratorija u međulaboratorijskim usporedbenim ispitivanjima. Na osnovu prikazanih rezultata može se zaključiti da je odabrani laboratorij u promatranom razdoblju uspješno provodio kontrolu kvalitete rezultata analitičkih metoda za sva četiri ispitivana parametra, budući da dobiveni rezultati referentnog materijala nisu prelazili zadane granične vrijednosti. Laboratorij je uspješno sudjelovao i u međulaboratorijskim usporedbenim ispitivanjima, što je potvrđeno dobivenim Z-vrijednostima koje su bile između -2, 00 i +2, 00 za sve ispitivane parametre. Primjenom predstavljenih postupaka kontrole postignuta je visoka kvaliteta rezultata ispitivanja.

Vinogorje Kaštela–Trogir je područje uzgoja mnogih autohtonih sorti vinove loze. Od crnog sortimenta najzastupljenija je sorta Babica. Nakon što je DNK analizom utvrđena genetska istovjetnost kalifornijskog Zinfandela, te talijanskog Primitiva s Tribidragom započinje njegova revitalizacija. Iz komercijalnih razloga površine pod Tribidragom se povećavaju, a Babice i ostalih sorti opadaju. Dok se zadnjih godina pojavljuju neke nove okolnosti koje otežavaju uzgoj Tribidraga, Babica zaslužuje biti predmetom vinogradarskog interesa, tim više što sve mogućnosti njenog enološkog potencijala nisu u potpunosti iskorištene., In the vineyard area of Kaštela – Trogir many autochthonous grapevine cultivars are cultivated. Among red wine cultivars Babica cultivar has been mostly represented. After DNA analysis proved that Tribidrag is genetically identical with Californian Zinfandel and Italian Primitivo cultivars, its revitalisation has begun. Because of commercial reasons Tribidrag grape growing areas have been increasing while those cultivating Babica and other grape varieties have been gradually decreasing. It has been observed that recently some new difficulties in cultivation of Tribidrag cultivar have appeared, whereas Babica deserves to become the focus of vine growing interest as all the possibilities of its enological potential are not fully exploited.

Analizirano je pet vina Škrlet proizvedenih od istoimene autohtone sorte grožđa u Volodersko-Ivanićgradskom vinogorju (podregija Moslavina) i Petrinjskom vinogorju (podregija Pokuplje). Primjenom standardnih metoda analize određene su koncentracije reducirajućih šećera, ukupnih kiselina, hlapljivih kiselina, ekstrakta te slobodnog, vezanog i ukupnog SO2. Volumni udio etanola određen je primjenom dviju metoda - tekućinskom kromatografijom visoke djelotvornosti (HPLC) i plinskom kromatografijom (GC). Za određivanje udjela jabučne kiseline, mliječne kiseline i glicerola primijenjena je HPLC metoda. Većina uzoraka zadovoljila je Pravilnikom propisane kriterije za kvalitetna vina, dok je jedan odstupao s obzirom na koncentracije glicerola i ukupnih kiselina.

Nowadays, incidents related to intentional contamination of food products are a huge problem in the whole food supply chain. Therefore, it is necessary to raise awareness of food defence at every level of the food chain, from farm to fork, from government and academic institutions to retail chains, the media and consumers. The principles of food defence can be implemented at every level of the food chain. Food defence contributes to the mitigation of potential risks in intentional contamination and food fraud, which can have a harmful effect on humans and public health, business, economy, etc. The requirement for the implementation of food defence comes from retail chains. They require food companies to be certified according to the standards of the food safety system such as those supported by the Global Food Safety Initiative. Although food defence is an inevitable step in enhancing and strengthening the whole food safety system, on a global scale, an insufficient number of countries have incorporated food defence principles into their legal frameworks. The intention of this review article is to increase awareness of food defence in food industry.

Volatile aroma compounds production by two autochthonous Saccharomyces cerevisiae strains, isolated from Istria region, and three other yeast strains (Saccharomyces bayanus and two commercial Saccharomyces cerevisiae wine yeasts) was investigated on a small scale using synthetic VP4 medium and Graševina must at 12 and 20°C. The results obtained by gas chromatography analyses were compared with the aroma production properties of the native microflora, remaining after Graševina must sulphiting. In both media and at both temperatures, the wine yeasts investigated showed different metabolic profiles regarding the tested volatile aroma compounds, which should be taken in consideration for autochthonous wine production. Although the synthetic medium proved to be appropriate for the investigation of the fermentative properties, the determination of secondary aroma production by wine yeasts has to be conducted by must fermentation or possibly by fermentation of another synthetic medium whose composition would be more similar to must.

Solid-phase microextraction (SPME) was examined to investigate volatiles in tomatoes and tomato products. Aroma volatiles and differences in volatile composition of different varieties of fresh tomatoes and several commercial tomato products, such as tomato juice, tomato puree, tomato paste and canned diced tomatoes, were analysed by a manual headspace SPME technique coupled with gas chromatography (GC–FID and GC–MS). Fresh and processed tomato aroma was composed of terpenes and lactones, esters, carbonyls and alcohols, sulphur compounds, free acids and oxygencontaining heterocyclic compounds. In most samples of processed tomatoes, lower relative concentrations of volatiles than in fresh tomato samples were determined, but in some cases (especially in samples of tomato juice) higher concentrations were observed. The most important difference between fresh tomato and processed tomato aroma was the almost complete loss of cis-3-hexenal and the presence of furfural in tomato products. On the basis of the aromatic profiles obtained by GC analysis, relationships between fresh and processed tomato samples were obtained, using multivariate PCA statistical analysis. Copyright © 2007 John Wiley & Sons, Ltd.

The influence of the addition of two sugars (trehalose and sucrose) on the retention of volatiles responsible for the characteristic aroma in dehydrated apricot puree was studied. Aroma compounds of fresh and both freeze dried and foam-mat dried apricot puree were analyzed by manual headspace solid-phase microextraction (SPME) coupled with gas chromatography (GC-FID and GC-MS). The best retention of aroma compounds in dehydrated apricot puree was obtained when trehalose was added, regardless of the dehydration process used (freeze drying or foam-mat drying) although, generally, a much higher retention of flavour volatiles was obtained in freeze dried purees. Principal Component Analysis (PCA) and Cluster Analysis (CA) were applied to all apricot purees studied to obtain a more simplified view of the relationship among the aroma compounds in dehydrated apricot purees. This study gives further insights into the mechanisms that occur when trehalose is applied as an additive and will enable the development of new processes to maximize this effect and to produce superior dried products.

The prospects of quality young wine distillates production have been examined. The base wine was produced from Vitis vinifera L. quantitatively dominating grape varieties within the group of the recommended and permitted varieties of Kutjevo vineyards, located in the eastern part of the continental Croatia. Characterisation of wine and distillates was based on chemical and instrumental methods and on their sensory evaluation. Volatile compounds were analysed and identified by GC-FID and GC-MS. The wine varieties Rhine riesling, Müller Thurgau and Riesling have the potential for the production of quality distillates, suitable for maturation. Pinot white, Traminer and Chardonnay give more acceptable wines than distillates and it is therefore not advisable to use them for distillates production, while the varieties Pinot gris, Frankovka and Steinschiller are not suitable for the production of distillates.

The phytic acid content and distribution of phosphorous during cereal flaking were determined as well as the level of some minerals, and the molar ratios of phytic acid ; zinc were calculated. statistical analyses showed that there were no differences in the amount of total phosphorous, between oats and wheat and between rye and barley. The phytic/non-phytic phosphorous ratio was about 3 in wheat and oats, about 2 in barley and about 13 in rye. The technological processing did not affect P

In order to investigate the composition of secondary aroma compounds of fresh grape marc distillates as a result of variety and production technology, 30 samples (6 varieties×5 samples) were analysed. White grape marc samples from Malvazija istarska, Chardonnay and Muscat Blanc were obtained as by-products in standard white wine production, while red grape marc samples from Teran and Cabernet Sauvignon were obtained after standard red wine production procedures. Marc from red grape variety Muškat ruža porečki was obtained during the production of rosé wines. All fermented marc samples were distilled using a traditional copper alembic. The obtained distillates were subjected to GC/MS and GC/FID analyses. Malvazija istarska distillates exhibited exceptionally high methanol content. Distillates from white grape varieties were found to be characterized by higher C6 alcohol and 1-propanol concentrations, while red grape distillates contained higher amounts of the majority of alcohols, acids, and esters. In Muškat ruža distillates intermediate concentrations of many important aroma compounds were found. It was concluded that differences in the production technology parameters, depending on the variety, resulted in differences in secondary aroma profiles, most evident between distillates from white and red varieties. These findings were confirmed applying stepwise linear discriminant analysis (SLDA), which resulted in 100 % correct classification of distillates according to the variety and corresponding production technology., Da bi se ispitao sastav spojeva sekundarne arome u svježim rakijama komovicama uzrokovane sortom i odgovarajućom tehnologijom proizvodnje, analizirano je 30 uzoraka (6 sorti×5 uzoraka). Uzorci komine bijelih sorata grožđa Malvazija istarska, Chardonnay i Muscat Blanc dobiveni su kao nusproizvod u standardnoj proizvodnji bijeloga vina, dok su uzorci komine sorata crnoga grožđa Teran i Cabernet Sauvignon dobiveni standardnim postupkom proizvodnje crnoga vina. Uzorci komine sorte crnoga grožđa Muškat ruža porečki dobiveni su pri proizvodnji rosé vina. Svi uzorci prevrele komine destilirani su u tradicionalnom bakrenom kotlu za destilaciju. Dobivene rakije komovice podvrgnute su GC/MS i GC/FID analizi. Komovice od sorte Malvazija istarska imale su iznimno veliki udjel metanola, a od sorata bijeloga grožđa veće koncentracije C6 alkohola i 1-propanola, dok su komovice od crnih sorata sadržavale veću količinu većine alkohola, kiselina i estera. U komovicama od Muškat ruže porečke pronađene su srednje koncentracije mnogih važnih spojeva arome. Zaključeno je da su različiti uvjeti proizvodnje, koji ovise o sorti, uzrokovali različitu sekundarnu aromu, najizraženiju u komovicama od sorata bijeloga i crnoga grožđa. Te su spoznaje provjerene primjenom postupne linearne diskriminantne analize koja je omogućila 100 % točnu klasifikaciju rakija komovica na osnovi sorte i odgovarajuće tehnologije proizvodnje.

In order to investigate the varietal aroma compound composition of monovarietal grape marc distillates made from six different varieties (Vitis vinifera L.) in the region of Istria (Croatia), 30 samples were subjected to GC/MS and GC/FID analysis. A total of 73 compounds were identified: 45 monoterpenes, 20 sesquiterpenes, 3 diterpenes, and 5 C13-norisoprenoids. The largest number and the highest concentration of monoterpenes were found in Muscat Blanc, followed by Rose Muscat of Poreč (Muškat ruža porečki)distillates, which were both characterized as highly aromatic. Lower, but still significant monoterpenol content was determined in distillates made from Istrian Malvasia (Malvazija istarska) grape marc. Chardonnay, Cabernet Sauvignon and Teran distillates exhibited poorer monoterpene profiles, while Teran distillates contained elevated sesquiterpene concentrations. It was concluded that investigated monovarietal grape marc distillates significantly differ in varietal aroma compound composition. Stepwise linear discriminant analysis provided efficient discrimination models, and extracted various monoterpenes, sesquiterpenes and C13-norisoprenoids as important differentiators of distillates according to varietal origin.

Prošek is a traditional dessert wine from the coastal region of Croatia made from partially dried grapes. There is very little literature data about the chemical composition and sensory properties of Prošek, so an experimental production from the dried grapes of Plavac mali cultivar has been done using native and induced alcoholic fermentations. To determine the volatile compounds, gas chromatography with flame ionisation detector (GC/FID) was used on the samples prepared with solid phase microextraction (SPME). Higher alcohols, esters, carbonyl compounds and volatile acids were determined in the wine samples. Wines were grouped according to the production method using principal component analysis (PCA). It was found that Prošek wines produced with native and induced alcoholic fermentation differ in their volatile compounds. Descriptive sensory analysis was applied to show the sensory properties of Prošek wine, whose characteristic aromas include those of dried fruit (raisins), red berries, honey, chocolate and vanilla. A significant difference depending on the type of fermentation was determined in two sensory attributes, strawberry jam aroma and fullness., Prošek je tradicionalno desertno vino koje se proizvodi od prosušenoga grožđa u obalnom području Hrvatske. Budući da postoji malo literaturnih podataka o kemijskom sastavu i senzornim svojstvima prošeka, provedena je eksperimentalna proizvodnja od sorte Plavac mali koristeći spontano i inducirano alkoholno vrenje. Fermentacijski hlapljivi spojevi određivani su plinskom kromatografijom sa plamenim ionizacijskim detektorom (engl. gas chromatography with flame ionisation detector - GC/FID) uz pripremu uzorka pomoću mikroekstrakcije na čvrstoj fazi (engl. solid phase microextraction - SPME). U vinima su određeni viši alkoholi, esteri, karbonilni spojevi i hlapljive kiseline. Analizom glavnih komponenata (engl. principal component analysis – PCA) vina su razvrstana po načinu proizvodnje. Utvrđeno je da se prošek proizveden spontanim i induciranim alkoholnim vrenjem razlikuje po hlapljivim sastojcima. Senzornom analizom prošeka uočena je aroma po sušenom voću (grožđu), crvenom bobičastom voću, medu, čokoladi i vaniliji. S obzirom na vrstu alkoholnog vrenja najveća je razlika utvrđena u aromi džema od jagoda i punoći okusa vina.

Knowledge of the content of heavy metals is important because of their impact on the stability of wine or on the health of consumers. The presence of heavy metals in wines is a consequence of action various factors such as conditions of cultivation and processing of grapes and production, stabilization or storage of wine. In this work determination of heavy metals (Cu, Fe, Zn and Pb) content in red wines was carried out. Selected wine was Plavac mali, Croatian autochthonous sort, produced by various producers during the three consecutive vintages. The aim of this work was to examine whether the wines produced in different vintage, and by various producers, vary according the content of heavy metals. To determination of heavy metals content, atomic absorption spectrometry (AAS) was used. Content of heavy metals ranged between 0, 235-1, 122 mg/L (Cu), 0, 809 – 6, 202 mg/L (Fe), 0, 266-2, 434 mg/L (Zn) and 0, 107 - 0, 3355 mg/L (Pb). Data analysis showed statistically significant differences only between producers for iron and copper content.

Solid-phase extraction (SPE) procedure on octadecylsilica (C18) was developed for accumulation of volatile compounds from grape distillates. The procedure was optimised for final analysis by capillary gas chromatography. At mass concentrations in model solutions ranging from 0.1 mg/l to 50 mg/l solid-phase extraction recoveries of all analytes ranged from 69 % for 2-phenylethanol to 102 % for capric acid, with RSD values from 2 to 9 %. SPE recoveries of internal standards to be added in the sample solution prior to extraction, higher alcohols 2-ethyl-1-hexanol and 1-undecanol, were 97 and 93 %, respectively, with RSD values of 3 %. Detection limits of analyzed compounds in model solutions ranged from 0.011 mg/l for isoamyl acetate to 0.037 mg/l for caproic acid. Method efficiency was tested in relation to acetic acid content, volume fraction of ethanol and possible matrix effects. A significant influence of matrix on SPE efficiency for geraniol, cis-2-hexen-1-ol and cis-3-hexen-1-ol was detected. For the same reason, 2-phenylethanol could not be determined by developed SPE method in samples of grape distillates. The developed solid-phase extraction method was successfuly applied to determine the differences in volatile compound content in different grape distillates produced by the distillation of crushed, pressed and fermented grapes.

Aroma is a phenomenon that occurrs when food and live organism mutually react during the process of consumption. Many factors influence the making of aroma of wine distillates (e.g. cognac) during the technological process of distillation. It is extremely difficult to bring an objective judgement on the influence of individual factors since aroma is very subjective in its nature. The possibility of objective assessment of the influence of grape varieties on wine distillate was performed in this work using a computer in processing the results of cromatographic analyses of aroma substances. The given results were verified by sensor analyses. The achieved results have shown that mathematical model for calculating aroma chromatogram similarity can be successfully used for objective assessment of the influence of individual factors on aroma of wine distillates and that grape varieties have significant impact on aroma and the quality of wine distillates., Aroma je fenomen koji se pojavljuje tijekom konzumiranja hrane u organizmu. Pri stvaranju ukupne kakvoće (tip cognac) vinskih destilata upravo taj fenomen ima dominirajuću, a vrlo često i odlučujuću ulogu. Na aromu vinskih destilata utječe mnogo činitelja tijekom njezina stvaranja u tehnološkom procesu proizvodnje. Međutim, objektivnu je prosudbu o utjecaju pojedinog činitelja iznimno teško donijeti jer aroma ima i subjektivni karakter. U ovom je radu ispitana mogućnost objektivne procjene utjecaja sorte na aromu vinskih destilata primjenom računala u obradbi kromatografskih rezultata analize tvari arome, a navedeni su rezultati provjereni senzorskim analizama. Dobiveni su rezultati pokazali da se matematički model za kompjutorsko izračunavanje sličnosti kromatograma arome može uspješno koristiti pri objektivnoj procjeni utjecaja pojedinih činitelja na aromu vinskih destilata, te da sorta grožđa bitno utječe na aromu i kakvoću vinskih destilata.

Cottage sir je svježi sir karakteristična oblika individualnih zrna veličine 3-12 mm. Može se koristiti kao dijetni sir, zbog minimalne količine mliječne masti (ali, bogat je bjelančevinama), ili kao "krem" sir, ako se prekrije nekom krem mješavinom, najčešće od vrhnja, uz različite dodatke (sol, povrče, voce i slično). Budući da se Cottage sir još uvijek ne proizvodi u Hrvatskoj, svrha ovog rada je ispitati prihvatljivost ovog proizvoda, nepoznatog većini potrošača u našoj zemlji. Uzorci Cottage sira proizvedeni su od obranog ili UF-obranog mlijeka (s oko 5 i 7% proteina) a tada, nakon ocjenjivanja senzorskih svojstava, oblikovani u zrna boljih karakteristika, koristili su se za pripravu uzoraka Krem Cottage sira. U radu je ispitana prihvatljivost slanih zrnaca Cottage sira proizvedenih ispiranjem gruša u slanoj otopini, kao i prihvatljivost različitih uzoraka Cottage sira pomiješanog mješavinom vrhnja i različitih dodataka - Krem Cottage sir. Testirano je 40 potrošača (starih 20-60 godina). Oni su pripremljene uzorke Cottage sira ocijenili hedonističkom skalom Peryama (moguća ocjena 1-9), najčešćom metodom za istraživanje prihvatljivosti prehrambenih proizvoda., Cottage cheese is soft fresh cheese having characteristically shaped individual granules of approximately 3-12 mm. Cheese may be used such as dietetic food, owning to its minimum milk fat quantity, and having plenty of proteins, or such Creamed Cottage cheese, covered with some creaming mixtures (added salt, fruit, vegetables or something similar). Since Cottage cheese was not as yet produced in Croatia, the purpose of this paper is to investigate consumer's acceptability as it is unknown to many of our consumers. Cottage cheese samples were produced from skim milk and ultrafiltered skim milk (with 5 and 7% proteins) and then shaped as granules of better characteristics, according of sensory properties evaluation, used for preparation of Creamed Cottage cheese. Investigation is relative to the acceptability of Cottage cheese having salty granules and also to acceptability of Cottage cheese samples mixed with sour cream and different ingredients - Creamed Cottage cheese. Consumer's panel of 40 members (from 20 to 60 years old) evaluated Cottage cheese samples using a nine-point Hedonic scale, probably the most useful sensory method.

Possibility of applying non-destructive methods in determination of whey solids was investigated. The non-destructive methods used were: infrared spectroscopy, cryoscopy, conductometry and gravimetric method as a referent method. With statistical interpretation of results the stochastic relation of variable between independent variable (investigated method) and dependent variable (referent method) was established. The stochastic relation showed satisfactory dependency of variables with linear equation: Y = b0X0 + b1x1 + ε. Determination coefficient verified model's efficacy. Infrared spectroscopy and cryoscopy were successful methods for determination of whey solids. Less precise were conductometry results., U radu je istražena mogućnost primjene nedestruktivnih metoda za određivanje suhe tvari sirutke. Korištene su slijedeće nedestruktivne metode: infracrvena spektroskopija, krioskopija i mjerenje elektroprovodljivosti, a kao referentna korištena je gravi-metrijska metoda. Statističkom obradom rezultata utvrđen je stohastički odnos između nezavisne varijable (provjeravana metoda) i zavisne varijable (referentna metoda). Stohastički odnos pokazao je zadovoljavajuću ovisnost varijabli linearnom funkcijom oblika Y=b0x0+b1x1+ε. Efikasnost modela je provjerena koeficijentom determinacije. Infracrvena spektroskopija i krioskopija bile su uspješne metode za određivanje suhe tvari sirutke. Rezultati dobiveni mjerenjem elektroprovodljivosti manje su precizni.