Enzyme Assisted Extraction of GAC Oil (<i>Momordica cochinchinensis Spreng</i>) from Dried Aril

Abstract

The purpose of this study was to improve the oil yield extracted from Gac fruit aril (Momordica cochinchinensis Spreng) by applying hydrolytic enzyme and to evaluate functional properties of the extracted Gac oil as influenced by different enzyme concentrations, incubation times and drying temperatures. Fresh Gac aril was treated with commercial enzyme (Viscozyme L) (0-0.2%) for a period of time (40-120 min), dried at a certain temperature (40-70°C) and then extracted with hexane for oil recovery. The best conditions for Gac aril extraction were 0.15% enzyme concentration, 100 min incubation time and drying temperature 60°C. Under these conditions, the oil recovery rate was of 96.39% with the total carotenoid content of 196.47 mg/100g. The resulted oil recovery rate (89.74%) and total carotenoid content (132.16 mg/100g) were significantly higher than those from the oil without enzymatic treatment. The peroxide value (8.73 meqO 2 /kg) and free fatty acid value (3.58 mg KOH/g oil) of the extracted Gac oil was comparable with oil by other methods. The Gac oil was rich in un-saturated fatty acids (oleic acid 48.99%, linoleic acid 21.09% and linolenic acid 0.86%), high in palmitic acid (24.18%) but low in stearic acid (3.52%). Application of Viscozyme L helped to increase significantly the oil recovery yield and total carotenoid content in oil, meanwhile, the oil was of good quality in terms of oxidative stability.