The Optimation of Anthocyanin Extraction From Butterfly Pea (Clitoria ternatea L.) Petal Using Response Surface Methodology.

Abstract

The Box-Behnken experimental design with Response Surface Methodology has been used in optimation of extraction process of anthocyanin from butterfly pea (Clitoria ternatea L.) petal. The extraction process was conducted with no light by using water. The ratio of fresh petal to water-HCl (pH 4.5) was 1:4 (w/v). The optimum process was defined as a set of extraction factors by using highest extract volume, anthocyanin and total phenol content as the selected parameters. The three factors were blanching time (0 to 12 minutes), extraction temperature (30 to 60oC) and extraction time (30 to 120 minutes). The research showed that all factors had significant effect to volume by following reduced 2-factor interaction model, while anthocyanin content and total phenol content was effected by following reduced quadratic model. Based on the models, the most efficient extraction process was 6 minutes for blanching time followed by 30 minutes of extraction time at 60oC. The antioxidant activity and stability during storage of the extract was also studied. The research showed that highest antioxidant activity of butterfly pea flower extract was reached at pH 1 (flavylium cation) followed by pH 4.5 (hemiketal form) and pH 7 (quinonoidal base). The study of stability showed that butterfly pea extract was very unstable at pH 12 to 14, both in room temperature and 4oC storage. The extracts with pH 1 to 11 at 4oC were much more stable compare to the room temperature. At room temperature, the highest stability showed by pH 1 and followed by pH 2. At 4oC the extracts with pH 1 to 2 and 7 to 11 were stable during 28 days storage.