Color Characteristic of Butterfly Pea (Clitoria ternatea L.) Anthocyanin Extracts and Brilliant Blue

Abstract

Butterfly pea (Clitoria ternatea L.) is one of potential anthocyanin sources which can be use as a food colorant. Anthocyanin extracts of butterfly pea was evaluated under different concentration, pH, tinctorial strength, and storage conditions and compared to synthetic colorant, brilliant blue. The structure of the largest molecule of anthocyanin in butterfly pea extracts, ternatin A1, made the extracts had a wide range of color spectrum from red in pH 1-2, purple to blue in pH 3-7, and yellow green in pH 8-14. The color of brilliant blue solution showed high stability from pH 1-12. The good stability of brilliant blue was also showed by the score of color density and degradation index.Chromaticity parameters of the samples were evaluated with the score of lightness, chroma, and hue. The hue score of anthocyanin extracts of butterfly pea at pH 4,5 and 7 showed blue to purple while brilliant blue showed blue color at same pH. When both of them were added to yogurt drink (pH 4,5) and rice (pH 7), the food added with anthocyanin extracts became blue-purple and brilliant blue gave bright blue color to the food.