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Aim of this study was to monitor the influence of drying method (naturally and chamber drying) and different sample preparation on supercritical CO2 extraction of oil from three grape seed varieties (Graševina, Zweigelt, Cabernet Sauvignon). The highest oil content was obtained from naturally dried screened and washed seeds of red variety Cabernet Sauvignon (14.85%) and lowest from chamber dried screened seeds of white variety Graševina (7.67%). Peroxide value ranged from 0.36 to 1.77 mmol O2/kg oil, free fatty acids 0.28-8.0%, and insoluble impurities 0.05-0.28%. Determined fatty acids were palmitic (6.98-11.58%), stearic (3.82-6.59%), oleic (14.90-19.97%) and linoleic acid (61.82-71.96%) in oil obtained from naturally dried seeds and 6.84-8.68%, 4.12-5.73%, 15.10-20.18% and 67.88-70.76% in oil from chamber dried seeds, respectively. In defatted cakes after supercritical CO2 extraction, protein and fibre content ranged from 8.17 to 9.85% and 34.58 to 43.96%, respectively. According to ANOVA results, sample preparation and drying method had statistically significant influence on grape seed oil extraction.

Postupkom hladnog prešanja iz koštica grožđa proizvodi se jestivo ulje visoke nutritivne vrijednosti. U ovom radu istraživan je utjecaj dodatka antioksidanasa (prirodni, sintetski) na oksidacijsku stabilnost hladno prešanog ulja koštica grožđa sorte Cabernet sauvignon crni. Od prirodnih antioksidanasa korišteni su ekstrakt zelenog čaja, ekstrakt ružmarina, ekstrakt nara, ekstrakt maslinovog lista, a od sintetskih BHA, PG i TBHQ. Određivanje oksidacijske stabilnosti ulja te utjecaj dodatka antioksidansa provedeno je testom ubrzane oksidacije ulja Schaal Oven testom. Rezultat oksidacije ulja izražen je peroksidnim brojem. Primjenom standardnih metoda u ulju su određeni osnovni parametri kvalitete (peroksidni broj, slobodne masne kiseline). Rezultati ispitivanja pokazuju da ekstrakt zelenog čaja i ekstrakt ružmarina (tip OxyLess CS) efikasnije štite ulje koštica grožđa od oksidacijskog kvarenja, a od sintetskih antioksidanasa TBHQ., The process of cold pressing grape seeds produces edible oil of high nutritional value. The paper investigated the effect of antioxidant supplementation (natural, synthetic) on the oxidative stability of cold pressed grape seed oil produced from the red grape variety Cabernet Sauvignon. The testing was carried out using the natural antioxidants green tea extract, rosemary extract, pomegranate extract and olive leaf extract, as well as the synthetic antioxidants BHA, PG and TBHQ. The oxidative stability of the oil and the effect of antioxidant supplementation were determined by the accelerated oil oxidation test, the Schaal Oven test. The result of the oil oxidation was expressed by the peroxide value. The basic quality parameters (peroxide value, free fatty acids) were determined by applying the standard methods to oil. The results of testing indicated that green tea extract and rosemary extract (type OxyLess CS) protect the grape seed oil from oxidative spoilage more effectively than synthetic antioxidants such as TBHQ.

Aim of this study was to monitor the influence of drying method (naturally and chamber drying) and different sample preparation on supercritical CO2 extraction of oil from three grape seed varieties (Graševina, Zweigelt, Cabernet Sauvignon). The highest oil content was obtained from naturally dried screened and washed seeds of red variety Cabernet Sauvignon (14.85%) and lowest from chamber dried screened seeds of white variety Graševina (7.67%). Peroxide value ranged from 0.36 to 1.77 mmol O2/kg oil, free fatty acids 0.28-8.0%, and insoluble impurities 0.05-0.28%. Determined fatty acids were palmitic (6.98-11.58%), stearic (3.82-6.59%), oleic (14.90-19.97%) and linoleic acid (61.82-71.96%) in oil obtained from naturally dried seeds and 6.84-8.68%, 4.12-5.73%, 15.10-20.18% and 67.88-70.76% in oil from chamber dried seeds, respectively. In defatted cakes after supercritical CO2 extraction, protein and fibre content ranged from 8.17 to 9.85% and 34.58 to 43.96%, respectively. According to ANOVA results, sample preparation and drying method had statistically significant influence on grape seed oil extraction., Cilj istraživanja bio je odrediti utjecaj načina sušenja (prirodno i u komornome sušioniku), kao i same pripreme sjemenki grožđa, na ekstrakciju ulja superkritičnim CO2 iz triju sorata grožđa (graševina, Zweigelt, Cabernet Sauvignon). Najveći udio ulja ekstrahiran je iz prirodno osušenih i prethodno opranih sjemenki grožđa crne sorte Cabernet Sauvignon (14,85%), dok je najmanje ulja dobiveno iz sjemenki osušenih u komornome sušioniku bijele sorte graševina (7,67%). Vrijednost peroksidnoga broja dobivenih ulja bila je u rasponu 0,36-1,77 mmol O2/kg, slobodne masne kiseline 0,28-8,0%, a netopljive nečistoće 0,05-0,28%. U ulju dobivenome iz prirodno osušenih sjemenki grožđa određene su sljedeće masne kiseline: palmitinska (6,98-11,58%), stearinska (3,82-6,59%), oleinska (14,90-19,97%) i linolna kiselina (61,82-71,96%). U ulju sjemenki grožđa prethodno osušenih u komori određene su sljedeće masne kiseline: palmitinska (6,84-8,68%), stearinska (4,12-5,73%), oleinska (15,10-20,18%) i linolna kiselina (67,88-70,76%). Nakon ekstrakcije superkritičnim CO2 u odmašćenim pogačama određen je udio proteina (8,17-9,85%) i vlakana (34,58-43,96%). Priprema uzorka i način sušenja sjemenki grožđa te sorta imaju značajan utjecaj na ekstrakciju i kvalitetu dobivenoga ulja.

Istraživanja formiranja netipične arome starenja vina (UTA) otkrila su značajnu korela¬ciju između UTA, koncentracije 2-aminoacetofenona (AAP) i vina dobivena od grožđa, koje je bilo pod utjecajem stresa (nedostatak vode ili opskrbe dušikom), vina od grožđa iz vinograda s visokim prinosima ili od ranije branoga grožđa. Cilj ovog istraživanja bio je istražiti različitu dozrelost grožđa i sintezu indol-3-octene kiseline i triptofana u moštu i vinu kod bijeloga kultivara vinove loze Rizling rajnski (Vitis vinifera L.). Tretmani u istraživanju bili su dva roka berbe grožđa (redovna i kasna berba) s dva različita položaja (Mladice i Hrnjevac). Indol-3-octena kiselina i triptofan u moštu i vinu određeni su metodom tekućinskom kromatografijom visoke djelotvornosti, uz fluore¬scentni detektor. Dozrijevanjem grožđa koncentracije indol-3-octene kiseline i tripto-fana smanjivale su se nezavisno od godine istraživanja te ispitivanoga položaja. Vina dobivena od kasnije branoga grožđa imaju manju mogućnost pojave netipične arome starenja vina u odnosu na ona redovne berbe., The research on forming atypical aging off-flavor in wines (UTA) was revealed a significant correlation between the UTA , the concentration of 2-aminoacetophenones (AAP) and the wines produced from grapes affected by stress (lack of water or nitrogen supply), wines from grapes grown in high yielding vineyards or earlier harvested grapes. The aim of this study was to explore the different grape ripeness and synthesis of indole-3-acetic acid and tryptophan in must and wine of white cultivar Rhine Rieslin (Vitis vinifera L.). Treatments in the research have been the two periods of the grape harvesting dates (regular and late harvesting) from two different locations (Mladice and Hrnjevac). Indole-3-acetic acid and tryptophan in must and wine were determined by high performance liquid chromatography with fluorescence detector. As the process of ripening was going on the concentration of indole-3-acetic acid and tryptophan in must and wines have been reduced regardless the year of research and vineyards positions. Wines produced from late harvested grapes have a lower possibility of the appearance of atypical aroma aging effect compared to the regular harvest.

Količine šećera i kiselina u moštu Rizling rajnski Kutjevačkog vinogorja praćene su u petogodišnjem razdoblju, od 1999.-2003. godine, na obiteljskom gospodarstvu Jakobović. Istraživanja ukazuju na variranje kakvoće moštova i vina zbog klimatskih uvjeta pojedine godine. Posebno se izdvajaju godine 2000. i 2003. godina, kada su količine šećera bile izrazito visoke, a sadržaj ukupnih kiselina znatno niži, što se kasnije odrazilo i na količine alkohola i kiselina u vinu, kao i na organoleptiku vina., Quantities of sugar and acid in the must of Riesling Rhine of Kutjevo vineyard area were observed on the Jakobovic Family Estate in the period of five years, from 1999 to 2003. The analysis shows varying quality of must and wine due to climatic conditions of a particular year. In the year 2000 and 2003 the quantities of sugar were exceptionally high and the content of all acids considerably lower which reflected later on the quantity of alcohol and acid in wine, as well as on organoleptic traits of wine.