Enzyme Assisted Extraction Of Gac Oil (Momordica Cochinchinensis Spreng)

Abstract

The purposes of this study were 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 % E/S) for a period of time (40 -120 min), dried at a certain temperature (40 -70 0C) and then extracted with hexane for oil recovery. The best conditions for Gac aril treatment were 0.15% E/S enzyme concentration, 100 min incubation time and drying temperature 600C. Under these conditions, the oil recovery rate was of 96.39 % with the total carotenoid content of 196.47 mg/100g. Both the resulted oil recovery rate and total carotenoid content were significantly higher than those from the oil without enzymatic treatment which were 89.74% and 132.16mg/100g, respectively. The peroxide value (8.73 meqO2/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%). Key words: enzyme, fatty acid composition, free fatty acid, Gac oil, peroxide value, total carotenoid content.