KARAKTERISTIK WARNA DAN AKTIVITAS ANTIOKSIDAN ANTOSIANIN UBI JALAR UNGU [Color Characteristics and Antioxidant Activity of Anthocyanin Extract from Purple Sweet Potato]

Abstract

Anthocyanin is a natural pigment that produces a range of colors, varying from red, purple, blue to yellow. The stability of the anthocyanin color is affected by pH, temperature, and light. Purple sweet potato is rich in anthocyanin, particularly a stable acylated anthocyanin. This research was conducted to study the effect of pH on color and antioxidative activity of anthocyanin extracted from purple sweet potatoes, harvested from Cilembu-Sumedang, Banjaran-Bandung, and Pakembangan-Kuningan. The experiments applied a completely randomized design with two replicates, analyzed in triplo. The results showed that the total number of monomeric anthocyanin in purple sweet potato harvested from Cilembu (3.78±0.08 mg cyanidin-3-glucoside/g dry weight, dw) was higher than that of Banjaran (3.18±0.01 mg/g) and Pakembangan (2.25±0.01 mg/g). The color of purple sweet potato anthocyanin extract was pH dependent. The color changed from red to faded red, purple, blue, green, and yellow as the pH increased from 1 to 14. The content of anthocyanins from three locations of purple sweet potatoes differed from each other (p<0.05). Radical scavenging activity and reducing power of purple sweet potato anthocyanins extracted at pH 1 was higher than that at pH 4.5 and pH 7.

Keywords

• anthocyanin
• antioxidant activity
• purple sweet potato