Optimization of enzyme aided extraction of anthocyanins from Prunus nepalensis L.

Abstract

A central composite design was employed to obtain the optimal conditions for enzyme assisted extraction (EAE) of anthocyanins from Prunus nepalensis L. using cellulase. Response surface methodology was used to evaluate the effects of temperature T (35–50 °C), cellulase enzyme concentration EC (5–15% E/S) and time t (2.50–4.00 hrs) on five responses anthocyanins recovery (TAC), total phenolic content (TPC), in vitro antioxidant activity (FRAP and DPPH) and total extract yield (TY). The optimum extraction conditions were found to be T = 45.6 °C, EC = 12.9% E/S and t = 3.98 h resulting in TY = 62.9 ± 1.40%, TAC = 9.89 ± 0.24 mg C3G equivalent/g dm, TPC = 8.32 ± 0.18 mg GAE/100 g dm with antioxidant capacity of 28.7 ± 0.12 mmol AAE/100g DM for FRAP and 91.2 ± 0.39% DPPH inhibition (20 mg/ml). EAE demonstrated higher anthocyanins recovery compared to conventional solvent extraction process. HPLC analysis showed the presence of cyanidin-3-O-glucoside, petunidin-3-O-glucoside, peonidin-3-O-glucoside and malvidin. FTIR and SEM analysis were also performed. The study provides an economical alternative for commercial extraction of anthocyanins from Sohiong fruit which can be used as a biocolourant for various food products. This offers immense potential for the fruit producers as well as food processors.