Optimization of phytochemicals production from the ginseng by-products using pressurized hot water: Experimental and dynamic modelling

This study investigates the influence of process conditions on pressurized hot water extraction (PHWE) to maximize the bioactive compounds, including total saponins (TS), total phenolic compounds (TP) and total antioxidants (TA), produced from ginseng by-product (GBP). Response surface methodology (RSM) was employed to study the influences of temperature [180-24 degrees C], pressure [15-45 bar], solid to liquid (S/L) ratio [0.04-0.09 g/mL], agitation speed [100-200 RPM], and reaction time [5-15 min]. Box-Behnken design (BBD) was used with five variables and three levels. The optimal conditions were 207 degrees C, 43.45 bar, S/L ratio of 0.04 g/mL, agitation speed of 199 RPM, and reaction time of 15 min. The obtained values of TS, TP and TA under these conditions were: 7.12 g Gin Re/100 g, 49.11 mg GAE/g, and 5.31 g TE/100 g, respectively. The optimized ginseng hydrolysate showed good antimicrobial and antihypertensive activities. Homogentisic and gentisic acid were the main phenolic compounds present in the ginseng hydrolysate. (C) 2016 Elsevier B.V. All rights reserved.