Optimization of pressurized liquid extraction and ultrasound methods for recovery of anthocyanins present in jambolan fruit (Syzygium cumini L.)

Abstract

This work aimed to evaluate and optimize the experimental conditions for the extraction of anthocyanins from jambolan (Syzygium cumini L) applying pressurized liquid extraction (PLE), bath ultrasound extraction (BUE), and probe ultrasound extraction (PUE). This work applied a non-factorial design to evaluate the extraction parameters and response surface methodology to optimize the extraction parameters regarding anthocyanin content. The experiments carried out using aqueous acidified ethanol solution (80% v/v) extracted more anthocyanins (14.4 mg c3g.g−1 DF) than using acidified methanol, acetone, or water. Among the methods, PUE resulted in the highest anthocyanins recovery. The optimal conditions obtained by RSM for PUE anthocyanin extraction from jambolan were: ultrasound power density of 5000 W/L, extraction time of 7.5 min, and 79.6% of ethanol. At optimal conditions, the concentration of anthocyanins was 60.5 mg c3g.g−1 DF. No statistical difference was found between the experimental value and the value predicted by the model (p > 0.05). Identification of the jambolan anthocyanins was carried out using UPLC-ESI-QTOF-MS. Delphinidin-3,5-diglucoside, petunidin-3,5-diglucoside, and malvidin-3,5-diglucoside were identified as the main anthocyanins in the ethanolic extracts, obtained by all three methods (PLE, BUE, and PUE).