Optimization of Prickly Pear Juice Clarification for Better Retention of Betalain and Color Properties

Abstract

Background: Prickly pear juices are considered as valuable ingredient for sports and energy drinks due to its higher amino acids contents, minerals and attractive red color. Hence, prickly pear fruit has received renewed interest for the production of juice. Up to date, relatively little work has been reported regarding the manufacturing of prickly pear products. Enzyme has proved to be the key element for producing clear and stable fruit juice. The present study aimed to optimize the processing parameters for enzymatic clarification of prickly pear juice. The results of this investigation are expected to provide the suitable process technology for the production of prickly pear juice with better retention of betalain content and color value. Methods: Prickly pear pulp was treated with pectinase enzyme at different concentrations (0.01-0.09%), incubation temperatures (40-60°C) and incubation time (60-180 min). The effect of enzymatic treatments on clarity, color index, betalain content and ascorbic acid content of juice were studied through response surface methodology by employing second order central composite rotatable design. Result: Response surface analysis determined the optimum condition for clarifying prickly pear juice as 0.036% enzyme concentration, 46°C incubation temperature and 112 min incubation time. At this condition, it was predicted to produce the prickly pear juice with clarity of 48.59% T, color index of 0.603 abs, betalain content of 542.93 mg/L of juice and ascorbic acid content of 9.35 mg/100 g with the desirability of 0.780.