A comparative study on the extraction of betalain rich phenolic compounds in cactus pear

Abstract

In recent years, consumer demands grow on non-artificial food colorants because of health concerns. Betalain is one of the most popular natural food colorant. The present study concentrated on the extraction of betalain rich bioactive compounds from cactus pear (Opuntia ficus-indica L.). For this purpose, conventional extraction (CE) and ultrasound assisted extraction (UAE) was compared in terms of some extraction parameters including extraction time (x1), extraction temperature (x2), percentage of ethanol in extraction solvent (x3), solid/solvent ratio (x4). Response surface methodology was used in conjunction with Box-Behnken design to optimize the extraction parameters.  In CE, the optimum extraction conditions were found as; x1=2.05 h, x2= 50°C, x3=80% and 1/x4= 22.60; optimal conditions were determined as; x1=30 min, x2= 49.99°C, x3=40% and 1/x4= 30 in UAE. Total betalain contents were 418.829 and 471.818 mg betalain/ kg dry matter, respectively in CE and UAE in optimum extraction conditions. It was found that bioactive compounds were extracted effectively in shorter time and lower solvent in UAE. According to results, UAE was superior method for extraction of betalains compared to CE.