Synergistic effects of Garcinia mangostana and Clitoria ternatea extract mixture on antioxidant activities, colour, and anthocyanin stabilities

Abstract

The present work determined the antioxidant activities, and colour and anthocyanin stabilities of Garcinia mangostana peel (GMP) and Clitoria ternatea flower (CTF) extract mixtures. The plants were extracted at three different ratios of GMP:CTF at three different extractant pH levels (3.0, 3.5, and 4.0). The highest synergistic effects of ORAC, FRAP, ABTS, and DPPH radical scavenging capacity were observed in the mixture of 25% GMP and 75% CTF (25GMP:75CTF) extracted at pH 3.5. Based on the kinetic degradation of anthocyanin, and the L*, C*, and h° values, 25GMP:75CTF extracted at pH 3.5 exhibited a significantly lower rate constant (-k = 2.27) and higher half-life (t1/2 = 5.09 h) over 100°C, thus indicating the most stable mixture ratio and extractant pH condition of those tested. Therefore, the mixture of GMP and CTF at a ratio of 25:75 and an extractant pH of 3.5 produced the most stable extract with a good synergistic effect.