Co-pigmentation of purple sweet potatos (ipomoea batatas l) anthocyanin extract using green tea extract

Abstract

Copigmentation is one of the methods to stabilize and enhance the anthocyanin.color. Green tea has the phenolic compounds (one of them is catechin) that potentially serves as co-pigment. In this study co-pigmentation of purple sweet potato (Ipomoea batatas L) anthocyanin extract with green tea extract were investigated. The anthocyanin was extracted with water at pH 2. Green tea extract was made by maceration in hot water by varying time. The co-pigmentation was conducted by varying ratio of anthocyanin.extract with green tea extract (1:1; 1: 2; 1: 3; 1: 4; and 1:5). The results showed that the total anthocyanin in anthocyanin extract from purple sweet potato was 1700 ppm, the total polyphenol in green tea extract was 10014 ppm. Green tea extract can be used as co- pigment for anthocyanin from purple sweet potato by evaluating the bathochromic effect (maximum wavelength shift, Δλmax) and hyperchromic effect (the increase of absorbance, ΔAmax). Green tea extract showed the best co-pigmentation in the ratio (1: 1) while the bathochromic effect (Δλmax) was 4 nm and hyperchromic effect Δmax) was 0.548.