The aim of this work was to determine the effect of different drying treatments: freeze-drying, room-drying, and oven-drying on the grape phenolic composition of the 'Regent' and 'Cabernet Sauvignon' ...varieties. After drying, the samples were grounded, submerged to ultrasound-assisted extraction, and analyzed with high-performance liquid chromatography (HPLC). This study demonstrated that the use of different drying methods significantly affects the content of polyphenols in grape skins extracts. The greatest content of anthocyanins-diglucoside was preserved using freeze-drying, i.e. 15706.86 mg/kg for 'Regent', while the content of anthocyanins-monoglucoside was best preserved by room-drying, i.e. 216778.68 and 9220.30 mg/kg for 'Regent' and 'Cabernet Sauvignon', respectively. The highest content of flavonol glycosides (2583.04 and 1429.64 mg/kg for 'Regent' and 'Cabernet Sauvignon', respectively), hydroxycinnamic acids (1303.31 and 544.88 mg/kg for 'Regent' and 'Cabernet Sauvignon', respectively), and stilbene (2321.52 and 79.36 mg/kg for 'Regent' and 'Cabernet Sauvignon', respectively) was observed in the oven-dried samples. By applying freeze-drying the most optimal content of flavan-3-ol was preserved. Contents of polyphenolic compounds in oven-dried samples after 6 months of storage were almost identical to those in the samples analyzed immediately after drying. The greatest rate of degradation was observed in the room-dried samples while it was moderate in the freeze-dried ones. The results of this experiment demonstrate that it is necessary to dry samples in different ways to obtain the highest content of a certain polyphenolic group of compounds. The application of a drying method is determined by the goal of the final dried product in terms of content and composition of different polyphenolic compounds; thus, the obtained results could have an application in scientific research and for commercial purposes as well.
Polifenolni sastav grožđa i vina predmet je brojnih istraživanja, ponajviše zbog utjecaja pojedinačnih polifenola na senzorna svojstva vina te njihovog blagotvornog učinka na ljudsko zdravlje. Zbog ...klimatskih promjena koje postaju učestalije sve više se susrećemo s problemom fenolne zrelosti grožđa. Stoga je cilj istraživanje bio utvrditi utjecaj inaktivnih kvasaca na dozrijevanje grožđa Plavine te postizanje optimalne fenolne zrelosti. Na početku fenofaze šare dio grožđa tretiran je inaktivnim kvascima (Lalvigne mature), a kao kontrolna varijanta poslužilo je grožđe sorte Plavina na kojoj nije proveden tretman. U uzorcima grožđa provedena je osnovna fizikalno-kemijska analiza te analiza aromatskog i polifenolonog sastava. Značajna razlika uočena je u koncentracijama petunidin-3-O-glukozida i peonidin-3-O-glukozida kao i kemferol-3-O-rutinozida te procijanidina B1 kod tretiranog grožđa dok je ukupna kiselost bila izraženija u kontrolnom tretmanu. U aromatskom profilu tretirano grožđe izdvojilo se većim sadržajem monoterpena dok su seskviterpeni bili zastupljeniji u kontrolnom tretmanu. S obzirom na proizvodna svojstva sorte Plavina kao što su tanka kožica, osjetljivost na bolesti, zbijen grozd i velike bobice s manjom mogućnosti nakupljanja suhe tvari, od kojih se najčešće proizvedu laganija, slabija obojena vina, manje bogata polifenolima, primijenjena tehnologija ukazuje na mogućnost unaprjeđenja kvalitativnih svojstava sorte Plavina a time i vina. Plavina, grožđe, polifenoli, inaktivni kvasci
Graševina bijela najzastupljenija je i gospodarski najvažnija sorta u Republici Hrvatskoj. Uzgaja se u vinogradarskim regijama Zapadna i Istočna kontinentalna Hrvatska. Njena prilagodljivost ...klimatskim uvjetima jedna je od brojnih karakteristika koje ovu sortu čine popularnom među vinogradarima. Uočena je unutarsortna varijabilnost među populacijom Graševine bijele zbog čega je 2004. godine pokrenut projekt klonske selekcije na području vinogorja Kutjevo. U razdoblju od 2004. do 2015. godine, odabrano je dvanaest klonskih kandidata koji su se istaknuli od ostatka populacije po pozitivnim osobinama. Ovih dvanaest klonskih kandidata posađeno na Vinogradarsko-vinarsko pokušalište Jazbina s ciljem daljnjeg proučavanja njihovih karakteristika te nastavka postupka individualne klonske selekcije. Nakon ulaska nasada u puni rod, provedeno je proučavanje najbitnijih gospodarskih karakteristika. Utvrđene su značajne razlike između klonova za sljedeća svojstva: prirod, broj grozdova po trsu, osnovni pokazatelji kakvoće mošta.
The Croatian native, Vitis vinifera L. cv. Grk, is one of only a few wine cultivars with a female flower, resulting in two types of berries in the cluster: fully developed seeded (~3.5 g) and ...undersized seedless (~0.7 g), both ripe at harvest. This study investigated the intravarietal variability of Grk and the impact of the different proportion of seedless berries on grape yield and quality of Grk clones. Significant differences in cluster proportions of seedless berries among Grk clone candidates were determined. A high positive correlation was found between the seedless berry proportion and single berry weight, must tartaric acid content, and free volatile terpenes. These results indicate that it is possible to select clones with a higher proportion of seedless berries, which can then be used to improve the wine quality of Grk.
We evaluated the response of eight economically important Croatian grapevine cultivars and studied the impact of their sanitary status on in vitro introduction, by comparing the response of healthy ...and virus-infected genotypes of one cultivar. Nodal explant survival on three media, M1 (half-strength MS), M2 (full-strength MS) or M3 (full-strength MS with 4.4 µM L⁻¹ benzylaminopurine) was measured after 2 weeks and regrowth after 8 weeks. After 8 weeks, average shoot length and node number were significantly higher on M2 compared to M1 and M3. M3 induced significantly shorter average internode length, compared to M1 and M2. Survival of one healthy and of five cultivar Plavac mali genotypes infected with GFLV, GLRaV-1, GLRaV-3, GLRaV-3+GVA and GLRaV-1+GLRaV-3 was 97.5 and 82.8–87.5%, respectively. Regrowth of the healthy genotype reached 95.5%, but dropped to 5.5–31.4% in infected ones. The healthy genotype showed significantly higher shoot length (6.3 cm) and node number (7.3) compared to infected genotypes, with shoot length between 1.2–2.6 cm and node number between 1.2–3.0. By contrast, internode length was not significantly different between the healthy and the infected genotypes. The present work represents the first successful in vitro introduction for three of the eight native Croatian cultivars studied.
Evaluation of the incidence of virus infections was conducted in two grapevine collection fields. The first was the National collection of Croatian native grapevine cultivars, situated at the ..."Jazbina" experimentation station in eastern Zagreb, where more than 120 different autochthonous grapevine cultivars are held, collected from different Croatian vine-growing regions. The second was a regional collection located in Risika, on the island of Krk (the North Adriatic region) containing 19 native cultivars from that region. During February 2009 from both collections, 95 plants were selected and tested for presence of eight viruses by ELISA, including: Arabis mosaic virus (ArMV), Grapevine fanleaf virus (GFLV), Grapevine fleck virus (GFkV), Grapevine leafroll-associated virus 1 (GLRaV-1), Grapevine leafroll-associated virus 2 (GLRaV-2), Grapevine leafroll-associated virus 3 (GLRaV-3), Grapevine virus A (GVA) and Grapevine virus B (GVB). The dominant virus in both collections was GLRaV-3, present in 75 vines (78.9%) in the National collection and in 73 vines (76.8%) in the Risika collection. The second most frequent virus in the National collection was GVA (60.0%), followed by GLRaV-1 (29.5%), GFkV (24.2%), GFLV (17.9%), ArMV (12.6%), GLRaV-2 and GVB (2.1%). In the Risika collection, GLRaV-3 was followed by GFLV (42.1%), GFkV (36.8%), GVA (32.6%), ArMV (23.2%), GLRaV-1 (11.6%), GLRaV-2 and GVB (1.1%). Mixed infections with two, three of four different viruses were also common in both collections. In the National collection the most common mixed infections were GLRaV-3 + GVA (15.8%) and GLRaV-1 + GLRaV-3 + GVA (14.7%), while in the Risika collection dominant were mixed infections with GLRaV-3 + GVA (10.5%) and GFLV + GLRaV-3 (8.4%). Free of all eight tested viruses were ten vines (10.5%) in the National collection and only seven vines (7.4%) in the Risika collection. This investigation has demonstrated that there has been deteriorated sanitary status of Croatian autochthonous cultivars, and indicates the need for the production of certified virus-free planting material.
•Varieties with different GEN-GEO background have different polyphenolic profiles.•The most abundant classes of phenols are anthocyanins, flavan-3-ols, and flavonols.•Polyphenolic profiles ...discriminated GEN-GEO groups.
Relevant aspect of wine geographic origin is related to grapevine varieties used for wine production in specific wine country or region. The grapevine germplasm is highly variable and classified into geographic groups. These classifications were recently confirmed using genetic studies, and further classified varieties into geographic-genetic (GEN-GEO) groups. Polyphenolic compounds are important secondary metabolites in grapes and have an important impact on wine quality and sensory properties. The aim of this research was to investigate the polyphenolic profiles of 50 grape varieties from different GEN-GEO groups. The groups were C2 (varieties from Italy and France), C7 (varieties from Croatia), C8 (varieties from Spain and Portugal). Polyphenolic compounds analysed belonged to the classes of anthocyanins, flavan-3-ols, flavonols, phenolic acids, and stilbenes. The most abundant classes of polyphenols were anthocyanins, followed by flavan-3-ols and flavonols. Using discriminant analysis, the genetic-geographic groups were clearly separated based on their polyphenolic profiles, with all classes of compounds contributing to discrimination.
Moderna vinogradarska i vinarska proizvodnja bazira se na dominantnom korištenju malog broja dobro poznatih sorata koje pripadaju plemenitoj vrsti vinove loze (Vitis vinifera L.), a koje su izuzetno ...osjetljive na glavne bolesti prisutne u uzgoju kao što su plamenjača (Plasmopara viticola Berk and Curt.) i pepelnica (Erysiphe necator Schwein.). Promjene sortimenta u uzgoju veoma su spore zbog konzervativnog i tradicionalnog stava proizvođača kao i potrošača grožđa i vina. Vinogradarska je proizvodnja jedan od najvećih potrošača pesticida, posebno fungicida i insekticida u odnosu na sve druge vrste proizvodnih sustava u poljoprivredi i kao takva ima izuzetno negativan utjecaj na okoliš, ali i zdravlje ljudi koji rade u vinogradarskom sektoru. Danas su u svijetu pokrenuti brojni oplemenjivački programi s ciljem stvaranja novih sorti otpornih na bolesti koje će svojom kvalitetom i drugim karakteristikama biti usporedive s tradicionalnim sortama pojedinih područja. U ovom radu iznesene su najvažnije oplemenjivačke metode i programi koji se danas provode na vinovoj lozi u Europi.
The aromatic and sensory profiles of monovarietal sparkling ciders made according to the modified Méthode Ancestrale or Pétillant Naturel (Pét-Nat) method were established. Three Croatian traditional ...apple varieties (‘Božićnica’, ‘Bobovac’, and ‘Crvenka’) were basic raw materials for Pét-Nat ciders in this study. The basic apple must and cider parameters were determined by applying OIV methods and nitrogenous compounds, total phenols, and color parameters were analyzed by spectrophotometer. Volatile compounds in final Pét-Nat ciders were determined by SPME-Arrow-GC/MS method and Odor Active Values (OAV) were calculated. The results show that variety significantly altered the pH value, color, aromatic and sensory profile of Pét-Nat ciders. The main contributors (OAV > 1) to the aroma of all Pét-Nat ciders were 1-hexanol, 1-propanol, (6Z)-nonen-1-ol, 1-dodecanol, hexanoic, octanoic and isovaleric acid, citronellol, ethyl hexanoate, ethyl butanoate, ethyl-9-decenoate and isoamyl acetate, eugenol and methionol. ‘Božićnica’ Pét-Nat was differentiated by a high concentration of 1-decanol and 4-ethylphenol, ‘Bobovac’ by 4-vinyl guaiacol and ‘Crvenka’ by 4-ethyl guaiacol. Sensory analysis showed that the highest rated overall quality was attributed to ‘Crvenka’ Pét-Nat cider, with the high-quality color, fruity odor (‘apple’,’apple juice/compote’, ‘pineapple’, and ‘buttery’) and well-balanced taste. This research demonstrates the possibilities in the production of natural sparkling cider from traditional Croatian apple varieties by analyzing the composition and quality of the final product for the first time.
Grape skin contains large amounts of different flavonoids so it can be used for their recovery. Optimization of enzyme-assisted extraction of flavonoids was conducted using oenological enzyme ...preparations with respect to enzyme dosage, temperature, extraction time, pH, and enzyme preparation. Optimal conditions were obtained using enzyme preparation Lallzyme EX-V, at the temperature of 45°C, time of 3 h, pH 2.0, and enzyme dosage of 10.52 mg/g. The new optimized extraction method is less expensive, simple, accurate, and selective for the recovery of simple flavonoids. It is based on an environmentally-friendly extraction solvent which may provide a valuable alternative to conventional methods.
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