Production of natural dyes from black rice bran extract on solid to solvent ratio and various of pH solvent

Abstract

Black rice bran is a byproduct of black rice removal process. It has the potential to be a source of natural dyes. The objective of this study is to evaluate the effect of solid to solvent ratio (1:10, 1:15 and 1:20) and various pH solvents (3,4,5, and 6) on characteristics of natural dyes from black rice bran extract and determine the best treatment to produce natural dyes from rice black bran extract. Extraction process used maceration method at ambient temperature. The experiment was designed using factorial randomized block design, and if there was a treatment that had a significant effect, it was continued with a Duncan test. The result showed that the solid to solvent ratio, various pH solvent, and their interactions had a significant effect on yield, anthocyanin content, and colors (L∗, a∗ and b∗). The best treatment is solid to solvent 1:10 and the value of pH 3, with characteristic 9,45% yield, 596,94 mg/l anthocyanin, 810,56 mg GAE/100 g polyphenol, and color (L∗ value 51.53, a value 26.93, b value 42.13).