engleski

Characterization of seed and skin proanthocyanidins in two Croatian wine grapes (Plavac mali and Babić)

The proanthocyanidin compositions of seeds and skins in two Croatian (Vitis vinifera L.) varieties Plavac mali and Babić from 2010 vintage were reported. Seeds and skins proanthocyanidins were extracted using acetone-water (80:20, v:v) followed by methanol-water (60:40, v:v) and separated in two fractions: monomeric/oligomeric and polymeric fraction. Compositions of both, seeds and skins proanthocyanidins fractions were evaluated. Monomers and oligomers in seeds and skins were identified and quantified by HPLC-UV-Fluo/MS. Structural characteristics including mean degree of polymerization (mDP), percentage of galloylation (%G) and percentage of prodelphinidins (%P) were determined in all fractions by phloroglucinolysis. Results showed that two varieties can be discriminated according to proanthocyanidin composition. In seeds, significant differences in individual procyanidins were observed for concentrations of B1 and B4 (p<0.05). Concerning structural characteristics mDP and %G, higher values were found in seeds of Babić, but significant differences were observed only for %G in oligomeric fraction. In skins, important significant differences were found in concentrations of all individual procyanidins where Plavac mali showed significantly higher values (p<0.001). Analysis of proanthocyanidin structural characteristics in both fractions of skins showed significantly higher values for %G and %P (p<0.05) in Plavac mali and significantly higher values for mDP (p<0.05) in Babić.

Grape seeds; grape skins; proanthocyanidins; phloroglucinolyisis; HPLC-UV-Fluo/MS

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