Optimisation of ultrasonic-assisted extraction of bioactive compounds from chokeberry pomace using response surface methodology.

Abstract

Chokeberry pomace is a valuable by-product of fruit processing because of its high levels    of phenolic compounds and anthocyanins. The study was aimed to optimise chokeberry pomace extraction of total phenolic content, total anthocyanin content and antioxidant activity using response surface methodology. Response surface methodology was used to evaluate the effect of the concentration of ethanol (in the range of 60–96%) and sonication time (from 10 to 30 min) as independent variables on total phenolic content, antioxidant capacity and total anthocyanin content as the response functions. The results showed that ethanol concentration, but not sonication time, had a significant influence on total phenolic content, antioxidant activity and total anthocyanin content. The optimal extraction conditions for total phenolic content (188.5 mg GAE/g DM) and antioxidant capacity (49.2 mM Tr/100 g DM) were 60% ethanol and 20 min sonication time. The optimal conditions in the case of total anthocyanin content (89.3 mg C3GE/g) were an 65% ethanol concentration and 13 min sonication time. The development of optimal extraction parameters should allow food producers to use efficient, cost-effective and environmentally friendly technology to isolate biologically active molecules from chokeberry pomace, while the selected extract could be a component of health-promoting bioactive products.