Optimization and comparison of heat- and ultrasound-assisted extraction methods for anthocyanin recovery from Sicana odorifera fruit epicarp

Abstract

AbstractThis study is aimed at maximizing the recovery of anthocyanins from Sicana odorifera fruit epicarp by heat- and ultrasound-assisted extraction (HAE and UAE, respectively) and at evaluating the in vitro bioactive properties of the anthocyanin-rich extracts obtained under optimized conditions. The optimization process utilized response surface methodology (RSM) through a central composite rotatory design (CCRD), combining time, ethanol percentage, and temperature or ultrasonic power. Response criteria included extraction yield (determined by gravimetry) and total anthocyanin content (TAC, quantified by HPLC-DAD). Under global optimum conditions, HAE (62 min, 90 °C, 27% ethanol) recovered 281 mg TAC/g extract with a yield of 23% (w/w) extract, while UAE (23 min, 500 W, 40% ethanol) yielded 200 mg TAC/g extract and 26% (w/w) extract, thus confirming the models’ predictive capacity. Furthermore, although HAE has produced extracts with higher anthocyanin concentrations, the cost-benefit associated with the processing conditions of each method must be considered. Both extracts showed antioxidant activity by inhibiting thiobarbituric acid reactive substances and oxidative hemolysis, but did not show anti-inflammatory, cytotoxic, and antimicrobial effects. Overall, this study promotes the upcycling of fruit waste into new ingredients for the food industry and other sectors that use anthocyanins, in line with sustainability and circular economy principles.