Bioactive compounds,pigments, antioxidant activity and antimicrobial activity of yellow prickly pear peels

The main goal of this research was to study the effects of pressure, extraction time and ethanol concentration on antioxidant activity, total phenolics, flavonoids, anthocyanins, carotenoids and betalains compounds extraction from yellow prickly pear peels. A Box–Behnken design and Response Surface Methodology were used to evaluate the effects and estimate the optimum extraction conditions. Antimicrobial activity was evaluated against Escherichia coli and Listeria innocua. Ethanol concentration was the variable that showed the highest effect on extraction yields but high-pressure increased extraction yields between 6% and 17%. Models showed good fitting and adequacy to the experimental data and the high correlation of models indicated that it can be employed to optimise extraction conditions. The experimental and predicted values differed <10% and the extracts inhibited the growth of both bacteria. High-pressure could be a promising extraction process to improve extraction of bioactives from prickly pear peels.