Identification and quantification of anthocyanins in Kyoho grape juice-making pomace, Cabernet Sauvignon grape winemaking pomace and their fresh skin.

BACKGROUND: The anthocyanins of Kyoho grape juice-making pomace, Cabernet Sauvignon grape winemaking pomace and their fresh skin were identified and quantified by high-performance liquid chromatography-tandem mass spectrometry, and the influence of processing on the anthocyanin profiles was investigated. RESULTS: Twenty-three and 16 anthocyanins were found in fresh skin of Kyoho and Cabernet Sauvignon grapes, respectively. Malvidin 3-(trans)-coumaroyl-5-diglucoside and malvidin 3-glucoside were the most abundant anthocyanin in fresh skin of Kyoho and Cabernet Sauvignon grapes, respectively. The cis and trans isomers of malvidin 3-coumaroyl-5-diglucoside are reported in Kyoho grape for the first time. In addition, the anthocyanin content of juice-making pomace of Kyoho grapes and winemaking pomace of Cabernet Sauvignon grapes was significantly lower than the fresh skin samples (p < 0.05). The percentage variation of non-acylated anthocyanins was lower than that of acylated anthocyanins in all pomace samples. CONCLUSION: Kyoho grape and Cabernet Sauvignon grape showed distinctive anthocyanin profiles. Juice-making pomace is a better source of anthocyanins for use in functional foods than winemaking pomace.