Optimization of conditions for anthocyanin hydrolysis from red wine using response surface methodology (RSM)

Optimization of conditions for anthocyanin hydrolysis from red wine was investigated using response surface methodology. The aglycon forms of the anthocyanins were quantified by high-performance liquid chromatography with diode array detection. The combined effects of three independent variables, HCl amount, heating temperature, and hydrolysis time, were studied using a 2(3) full-factorial central composite design. Anthocyanin hydrolysis yield depended mainly on the heating temperature and time of hydrolysis. HCl amount was the factor that least influenced the hydrolysis of anthocyanins. From experimental results, the maximum yield of anthocyanidins was reached with 9.8 mL of HCl (32% v/v), a heating temperature of 166.2 °C, and a hydrolysis time of 46.6 min. Five anthocyanidins, namely, delphinidin, cyanidin, petunidin, peonidin, and malvidin, were quantified in red wine. The reliability of the method was confirmed by recovery experiments, performed under optimal conditions. Recoveries indicated that anthocyanidins resisted the hydrolysis conditions.