Extraction of anthocyanins from muscat bailey A grape skins

Abstract

Anthocyanins from the skins of Muscat Bailey A grapes were extracted at different temperature in the presence of various concentrations of SO2. Diluted wine spirits containing 5 to 25% ethanol were used for the extraction. The extracts were separated by two-dimensional paper chromatography and were found to contain the following pigments, in a decreasing order of concentration, malvidin-3-monoglucoside, malvidin-3, 5-diglucoside acylated with p-coumaric acid, peonidin-3,5-diglucoside, malvidin-3,5-diglucoside, malvidin-3-monoglucoside acylated with p-coumaric acid, petunidin-3-monoglucoside, delphinidin-3-monoglucoside, and peonidin-3-monoglucoside. The red color of the extracts was mainly due to the extracted free anthocyanins. A very small amount of polymeric anthocyanins was formed during the extraction. The total phenol, and total and individual anthocyanin contents of the extract increased with increasing temperature as well as increasing SO2 and ethanol concentration. The rates of extraction of these anthocyanins varied with the kinds and amounts of the individual anthocyanins and the extraction conditions.