Optimization of various solvents for the extraction of anthocyanins from ‘sapinit’ (Philippine wild raspberry) using response surface methodology

‘Sapinit,’ officially known as the Philippine wild raspberry, is a promising source of natural colourants such as anthocyanins. In this study, extraction of anthocyanins from ‘sapinit’ using three solvent systems, namely, acidified acetone, acidified ethanol and acidified methanol were evaluated and optimized. The optimized extraction conditions were: 4°C, 150 mins, and 50% solid-to-liquid ratio (SLR) for the acidified acetone solvent system; 110°C, 10 mins, and 60% SLR for the acidified ethanol solvent system; and 26°C, 90 min, and 24% SLR for the acidified methanol system. These optimum conditions resulted in extracts with total monomeric anthocyanin content (TMA) of 540 mg cyanidin3-glucoside/L, 622 mg cyanidin-3-glucoside/L, and 89 mg cyanidin-3-glucoside/L, respectively. Validation procedures showed the generated models were able to predict the optimum TMA, with at most a 7% difference from the actual values. Moreover, acidified ethanol was found to be the most appropriate solvent for the extraction of anthocyanins from ‘sapinit.’