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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Healthy Processed Foods Research » Research » Publications at this Location » Publication #349161

Title: Phenolic composition of grape pomace skin of four grape cultivars

item Takeoka, Gary
item Dao, Lan
item ELKAHOUI, SALEM - Centre De Biotechnologie De Borj Cédria

Submitted to: International Journal of Food Sciences and Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/13/2018
Publication Date: 12/24/2018
Citation: Takeoka, G.R., Dao, L.T., Elkahoui, S. 2018. Phenolic composition of grape pomace skin of four grape cultivars. International Journal of Food Sciences and Nutrition. 3(6):246-249.

Interpretive Summary: Grapes are the world's largest fruit crop with an annual production of 63.85 million metric tons in 2014. About 80% of the grapes produced are used in winemaking. Grape pomace, a by-product of winemaking, consists of pressed skins, seeds, and stems which account for about 20% of the weight of the grape. Therefore, approximately 10 million tons of pomace are available annually from wineries. Disposal of winery by-products can have adverse environmental effects due to the presence of relatively high levels of phenolic compounds. However, phenolic compounds have potentially positive effects on human health such as anti-inflammatory, anti-ischemic, anti-obesity, and anti-platelet aggregating effects and other potentially disease preventing cellular actions. Recovery of the phenolic compounds as value-added by-products would be a possible solution to the environmental problems posed by large quantities of grape pomace generated annually. The objective of this study was to elucidate the phenolic compostion of grape pomace skins from the four red wine cultivars, Carignan, Merlot, Cabernet Sauvignon, and Syrah, obtained as by-products of winemaking. Carignan skin appeared to be the most promising source of phenolics of the cultivars studied due to its high concentrations of caftaric acid, rutin, quercetin 3-glucoside, kaempferol 3-glucoside and resveratrol.

Technical Abstract: Grape skins are a potential source of phenolics that can be used in the food, cosmetic, and pharmaceutical industries. The phenolic composition of grape pomace skin, a by-product of winemaking, was investigated. The air-dired pomace skin of four grape cultivars, Carignan, Merlot, Cabernet Sauvignon, and Syrah was studied. Carignan skin had the highest concentrations of caftaric acid (11.96±3.99 µg/g DW), rutin (9.23± 1.15 µg/g DW), quercetin 3-glucoside (97.76± 10.00 µg/g DW), kaempferol 3-glucoside (82.23± 33.22 µg/g DW) and resveratrol (4.83± 2.02 µg/g DW). Syrah skin had the highest concentration of gallic acid (36.33± 1.75 µg/g DW)while Cabernet Sauvignon skin had the highest concentration of catechin (12.83± 2.20 µg/g DW).