engleski

Polyphenolic potential of the rare Croatian variety Dobricic (Vitis vinifera L)

Croatia is very rich in grapevine (Vitis vinifera L.) biodiversity and many native varieties have been grown from ancient times, mostly along the Dalmatian coast. Many of the old native varieties have almost vanished and ‘Dobricic’ is one of them. This variety has a great potential to be used in planting new vineyards, but its oenological characteristics still have not been defined and its wine is still not available on the Croatian market. Polyphenolic compounds are of profound significance for determining technological and nutritional values as well as sensorial properties of grape varieties and wines. In this work, the phenolic potential of ‘Dobricic’ grapes has been evaluated. Two different vineyards with this variety were considered. Three samples from each vineyard were taken at the moment of harvest. Simulated maceration assays were carried out in wine model solutions containing 12 vol% ethanol, 5 g/L of tartaric acid and 50 mg/L of SO2, neutralized with 1/3 M NaOH to pH=3.2 in order to investigate the composition of the fraction of polyphenols that were extracted from the grape into the wine. For each sample, separate extraction assays were performed using the grape skin and seeds. The results show that grape extract of this rare native variety contains appreciable amount of total phenols, proanthocyanidins and catechins as well as anthocyanins. It was determined that grape skin is rich mainly in high-molecular-mass proanthocyanidins and anthocyanins. The skin contained higher concentration of low-molecular-mass proanthocyanidins than the seeds, as determined by vanillin index.

Dobricic’; polyphenols; grape; locations

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