Background: Grape berries are valuable nutraceuticals, due to the presence of different types of flavonoids as anthocyanins and flavonols, however, type and percentage of the components are influenced by genotype and environmental conditions.
Objective: To identify anthocyanins and flavonols of some important grape cultivars with different color profiles.
Methods: Berry skins of grape cultivars including Angoorab, Bidane-Ghermez, Fakhrie-Ghermez, Muskat of Hamburg, Flaim seedless, Sorkhak, and Ashe-Siahe-Shiraz were extracted using water/methanol as solvent. Anthocyanins and flavonols compositions were studied by HPLC.
Results: Highest total anthocyanin and total flavonol contents were 0.44 (Ashe-Siahe-Shiraz) and 0.67 (Angoorab) mg.100 g-1, respectively. Highest percentage of cyanidin in Bidane-Ghermez (91.6 %), peonidin in Fakhri-Ghermez (91.43 %), delphinidin in Flaim seedless (4.95 %), malvidin in Sorkhak (87.69 %) and petunidin in Muskat of Hamburg (4.36 %) were observed. Quercetin (61.21 in Ashe-Siahe-Shiraz to 87.37 % in Muskat of Hamburg) was the major flavonol, among all studied grape cultivars. Highest amounts of laricitrin in Sorkhak (16.73 %), myricetin in Ashe-Siahe-Shiraz (28.4 %), kaempferol in Flaim seedless (21.39 %) and isorhamnetin in Fakhrie-Ghermez (14.41 %) were observed. Also, estimation of hydroxylation and methylation activities showed that for both of the reactions, anthocyanins are much better substrates than flavonols.
Conclusion: The present study showed that studied grape cultivars are different for the content, composition and ratio of anthocyanins and flavonols and pattern of hydroxylation and methylation, which could lead to differences in their nutraceutical values specially their antioxidant activity, stability, solubility and color properties.