Optimization of microwave-assisted extraction of betacyanin from red dragon fruit peels
Abstract
Betacyanin has been widely used as natural coloring agents and dyes in food and textile industries to replace conventional toxic chemical pigments. In this study, the extraction of betacyanin from red dragon fruit peels was optimized using response surface methodology. Betacyanin was determined as the response to three independent variables, namely the ratio of extraction solvent to peels, microwave-assisted treatment time, and pH. The effect of acid ascorbic concentration during the storage of betacyanin extract, the total phenolic content, and DPPH radical scavenging activity were also investigated. The optimum extraction parameters are as follows: the ratio of extraction solvent to peels is 53% (v/w); extraction time is 91 s; pH is 5.3, with the betacyanin content being 72.13 mg/100 g peels. The betacyanin extract supplemented with 0.5% (w/v) ascorbic acid has the longest storage duration. Total phenolic concentration and DPPH radical scavenging activity (IC50) are 41.41 mg GAE/100 mL and 48.02 % (v/v), respectively.