OPTIMIZATION OF ULTRASONIC-ASSISTED EXTRACTION OF TOTAL ANTHOCYANINS FROM GRAPE PEEL USING RESPONSE SURFACE METHODOLOGY

Abstract

ABSTRACT Total anthocyanins from Campbell Early grape peel were extracted by using ultrasonic-assisted extraction technology. The experiments were performed according to a five-level, three-variable central composite rotatable design. The best possible combinations of extraction variables were obtained for the maximum extraction of total anthocyanins from grape peel using response surface methodology. The optimal extraction conditions include 52.35% ethanol, 45.14C temperature and 24.50 min time for the maximum total anthocyanins (6.26 mg/mL). Under these conditions, the experimental total anthocyanins were 6.24 mg/mL of the grape peel extract, which is well matched with the predicted values. PRACTICAL APPLICATION Anthocyanins are functional compounds and natural food colorants, which can replace synthetic colors. Grapes and grape residues are good sources of anthocyanins, and maximum recoveries of these compounds are possible by using optimized extraction processes. In our study, we have optimized the ultrasonic-assisted extraction of anthocyanins from grape peel by using central composite rotatable design and response surface methodology. This extraction method is an inexpensive, because of low instrumental involvement, simple and efficient alternative to conventional extraction techniques. Optimized extraction conditions predicted and validated in our study can be used for improved recovery of anthocyanins from grape peel.