Prosušivanje grožđa jedan je od ključnih postupaka u proizvodnji prošeka, desertnog vina s dugom tradicijom proizvodnje u Hrvatskoj. Tradicionalne sorte koje su se koristile u proizvodnji prošeka su ...autohtone sorte Dalmacije. Jedna od sorata koja se zbog svoje rasprostranjenosti i karakteristika može koristiti u proizvodnji prošeka je autohtona sorta 'Plavina'. Tradicionalna proizvodnja prošeka uključuje prosušivanje grožđa na zraku, međutim razvojem tehnologije otvorile su se i mogućnosti sušenja u kontroliranim uvjetima. Stoga je cilj rada bio utvrditi promjene kakvoće grožđa sorte 'Plavina crna' u kontroliranim uvjetima sušenja. Rezultati su pokazali kako je sušenjem došlo do koncentriranja sadržaja bobice te se povećao sadržaj šećera i organskih kiselina. Prosušivanjem se smanjio sadržaj polifenolnih i hlapljivih spojeva. Kako bi se utvrdio točan utjecaj na konačni proizvod, potrebna su daljnja istraživanja
Wine quality is influenced by the presence of over 500 different chemical compounds, with polyphenols having a crucial role in color intensity and tonality, astringency, mouthfeel, and overall ...impression formation, especially in red wine production. Their concentrations in wine can vary notably depending on the grape variety, the temperature and the length of maceration process, aging duration, and yeast selection. Therefore, in this work, the main goal was to determine the influence of five commercially available Saccharomyces yeasts provided from Lallemand, France and AEB, Italy, on the phenolic compound composition and chromatic parameters of Plavac mali wines produced from the grapes from coastal Dalmatia, grown at two different micro-locations. The achieved results pointed out the marked difference in individual polyphenol compound adsorption between tested yeasts. Fermol Super 16 was the one with the lowest and Lalvin D21 the strongest adsorption ability, regardless of vine growing location. These differences can be explained by the content of some anthocyanins (delphinidin and petunidin-3-O-glucoside) and gallic acid, and some flavan-3-ols. Tested strains also influenced wine color intensity, pointing out the possibility of modulating the style of a Plavac mali by the use of commercial yeasts.
The maceration process is one of the indispensable winemaking steps in red wine production that has a marked impact on phenolic compound extraction and can strongly influence the color and gustatory ...quality. Seed removal can have a substantial impact on the intensity of bitterness and astringency which are mainly influenced by the presence of flavanols. The main aim of this study was to investigate the influence of seed removal and extraction time on the phenolic composition, color parameters, and organoleptic properties of Plavac mali wines produced from the grapes from the Pelješac Peninsula. The achieved results showed that the control wines differ in terms of their highest content of total anthocyanins in both years and total flavonols in one year of investigation, while prolonged maceration without seeds decreases the concentration of phenolic acids as well as that of flavan-3-ols. A prolonged extraction time influenced the color intensity and tonality, moving it towards more yellow pigments. These changes could possibly be explained by the pronounced interaction between phenolic compounds and the formation of the new ones. Interestingly, seed removal probably diminished that change because the potential absorption of the anthocyanins by grape seeds and tannins were excluded. The highest quality was sensory defined in wines produced by prolonged maceration without seeds.
The
pathogen causes one of the most severe grapevine diseases, namely downy mildew. The response to
involves both visible symptoms and intricate metabolomic alterations, particularly in relation to ...volatile organic compounds, and depends on the degree of resistance of a particular variety. There are numerous native grapevine varieties in Croatia, and they vary in susceptibility to this oomycete. As previously reported, in vitro leaf disc bioassay and polyphenolic compound analysis are complementary methods that can be used to separate native varieties into various resistance classes. This research used the Solid Phase Microextraction-Arrow Gas Chromatography-Mass Spectrometry method to identify the early alterations in the VOCs in the leaves after
inoculation. Based on the absolute peak area of sesquiterpenes, some discrepancies between the sampling terms were noticed. The presence of certain chemical compounds such as humulene, ylangene, and
-farnesene helped distinguish the non-inoculated and inoculated samples. Although specific VOC responses to
infection of native varieties from various resistance classes could not be identified, the response of less susceptible native varieties and resistant controls was associated with an increase in the absolute peak area of several compounds, including geranylacetone,
-ocimene, and (
)-2-hexen-1-ol.
Grapevine badnavirus 1 (GBV-1) was recently discovered in grapevine using high throughput sequencing. In order to carry out large-scale testing that will allow for better insights into virus ...distribution, conventional and real-time PCR assays were developed using sequences both from previously known, and four newly characterized isolates. Throughout the growing season and dormancy, GBV-1 can be detected by real-time PCR using available tissue, with the possibility of false-negative results early in vegetation growth. GBV-1 real-time PCR analysis of 4302 grapevine samples from the Croatian continental and coastal wine-growing regions revealed 576 (~13.4%) positive vines. In the continental wine-growing region, virus incidence was confirmed in only two collection plantations, whereas in the coastal region, infection was confirmed in 30 commercial vineyards and one collection plantation. Infection rates ranged from 1.9 to 96% at the different sites, with predominantly autochthonous grapevine cultivars infected. Conventional PCR products obtained from 50 newly discovered GBV-1 isolates, containing the 375 nucleotides long portion of the reverse transcriptase gene, showed nucleotide and amino acid identities ranging from 94.1 to 100% and from 92.8 to 100%, respectively. The reconstructed phylogenetic tree positioned the GBV-1 isolates taken from the same vineyard close to each other indicating a possible local infection event, although the tree nodes were generally not well supported.
Seed extracts are becoming more important due to their beneficial biological activities. The main constituents of seed extracts are flavan-3-ols, compounds important in winemaking. The coastal region ...in Croatia is rich in native grapevine varieties, which are used in wine production. The aim of the research was to analyze the flavan-3-ol profiles of 20 native varieties, and to evaluate the potential use of grape seeds as a source of flavan-3-ols. The flavan-3-ols from seeds were analyzed by HPLC. The predicted yield of flavan-3-ols was calculated using the analyzed profiles. In total, eight compounds were identified, with the most abundant compounds being catechin, epicatechin, and procyanidin B2. In general, the red grape varieties had higher content of flavan-3-ols than the white varieties, which was confirmed by PCA. The coastal region could potentially yield up to 73.97 kg/ha of flavan-3-ols, depending on the variety. The results show the diversity of flavan-3-ol profiles among Croatian varieties and their potential usage as a source of valuable nutraceuticals.
The research of sanitary status and virus presence was conducted on three native Croatian grapevine varieties (Kujudžuša bijela, Zlatarica vrgorska and Trnjak crni) that are grown in Dalmatia region. ...The investigation was done on 492 vines from 31 vineyards. Vines were tested by ELISA (Enzyme-Linked Immunosorbent Assay) on four main economic viruses: arabis mosaic virus (ArMV), grapevine fanleaf virus (GFLV), grapevine leafroll-associated virus 1 and 3 (GLRaV–1, GLRaV-3) as a first step in clonal selection of these rare native grapevine varieties. Altogether, 40 vines were free of all tested viruses. The research confirms high rate of virus infection and eroded sanitary status of all investigated varieties. The above indicates necessity of implementation clonal and sanitary selection programme.
Sortni tioli su izrazito mirisni i poželjni spojevi arome koji doprinose mirisu vina aromama tropskog voća. Njihova koncentracija ovisi o brojnim čimbenicima, od ampelotehničkih i enoloških postupaka ...do uvjeta skladištenja. Sorta grožđa je jedan od najvažnijih čimbenika, pri čemu su utvrđene razlike i između samih klonova pojedine sorte. Cilj ovog rada bio je istražiti utjecaj klonova sorte Pošip na koncentraciju sortnih tiola u vinima. Rezultati su pokazali značajne razlike između klonova pri čemu su najviše koncentracije utvrđene u vinu proizvedenom od klona POŠ-124. Dobiveni rezultati ističu klonsku selekciju kao važan korak u proizvodnji vina različitih stilova.
Even though Saccharomyces cerevisiae starter cultures are still largely used nowadays, the non-Saccharomyces contribution is re-evaluated, showing positive enological characteristics. Among them, ...Lachancea thermotolerans is one of the key yeast species that are desired for their contribution to wine sensory characteristics. The main goal of this work was to explore the impact of L. thermotolerans commercial yeast strain used in sequential inoculation with S. cerevisiae commercial yeast on the main enological parameters and volatile aroma profile of Trnjak, Babić, Blatina, and Frankovka red wines and compare it with wines produced by the use of S. cerevisiae commercial yeast strain. In all sequential fermented wines, lactic acid concentrations were significantly higher, ranging from 0.20 mg/L in Trnjak up to 0.92 mg/L in Frankovka wines, while reducing alcohol levels from 0.1% v/v in Trnjak up to 0.9% v/v in Frankovka wines. Among volatile compounds, a significant increase of ethyl lactate and isobutyl acetate, geraniol, and geranyl acetate was detected in all wines made by use of L. thermotolerans. In Babić wines, the strongest influence of sequential fermentation was connected with higher total terpenes and total ester concentrations, while Trnjak sequentially fermented wines stood up with higher total aldehyde, volatile phenol, and total lactone concentrations. Control wines, regardless of variety, stood up with higher concentrations of total higher alcohols, especially isoamyl alcohol. The present work contributed to a better understanding of the fermentation possibilities of selected non-Saccharomyces strains in the overall red wine quality modeling.
Dalmatian vineyards host many autochthonous varieties. The phenolic profile, defined by the relative proportions of different phenolic compounds, is specific for each grape variety. The aim of this ...study was to determine and analyze the flavonoid compounds of twenty rare red grape varieties. Nineteen phenolic compounds, represented by anthocyanins, flavanols, and flavonols, were detected and quantified using HPLC in three consecutive vintages. The content of grape skin anthocyanins (10414.06 (Plavac mali crni)-19.58 (Trišnjavac) mg kg−1 d.w. of grape skin), flavonols (1742.08 (Pošip crni)-215.56 (Crljenak viški) mg kg−1 d.w. of grape skin), and flavan-3-ols (448.04 (Pošip crni)-87.88 (Glavinuša) mg kg−1 d.w. of grape skin) showed significant differences in investigated varieties. According to the investigated phenolic compounds, Pošip crni, Ljutun, Zadarka, Dobričić, Plavac mali crni, and Trnjak differed from other investigated varieties. These local varieties can be perceived as an alternative to widespread varieties in Dalmatia. This was shown by one of the first studies on phenolic profiles of (mostly) rare autochthonous varieties.
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