A Study On Effect Of Enzyme Treatment On The Yield Of Oil Obtained From H'mong Pumpkin Seed (Cucurbita Ficifolia) By Enzyme-Assisted Aqueous Extraction And Evaluation Of The Bioactive Properties Of The Final Oil

Abstract

The purpose of this study was to investigate the effect of enzymatic treatment in assisted aqueous extraction of oil from H’mong pumpkin seeds (Cucurbita ficifolia). Two enzymes (Viscozyme L and Alcalase) were screened for their effectiveness to release oil from H’mong pumpkin seed. The effect of several parameters consisting of enzyme concentration, temperature and duration for enzyme incubation on the oil yield were investigated. In detail, the oil yield obtained without enzyme was 14%. Meanwhile, for the Viscozyme L, the highest oil yield obtained in the conditions of 0.5 % (v/w of dried matter), at 50oC within 2h of incubation was 18.75%. For the Alcalse enzyme, the highest oil yield obtained in the condition of 1.5% (v/w of dried matter) at 50oC within 2h of incubation was 23.33%. As the result, the oil yield obtained by utilizing Alcalase (23.33%) was the best chosen of enzyme, which resulted in significant higher (p<0.05) than the control (without enzyme) (14%) and Viscozyme L (18.75%). Due to the capacity hydrolysis of protein of Alcalse which possibly causes the breakdown the protein of cotyledon cells and olesin bases membranes that surround lipid body and liberated oil. Although the enzymes enhanced the oil extraction, the oil yield was still significant (p<0.05) lower than that obtained by Sohxlet method. The bioactive properties of oil extracted from H’mong pumpkin seed by enzyme aqueous extraction were determined for total flavonoid content (15.834 mg/100g), radical scavenging activity (43.45%), total carotenoid content (6.168mg/100g), peroxide value (1.92 meqO2/kg) and free fatty acid (2.4%). Both peroxide and %FFA obtained by EAAE was lower than the Sohxlet method. The fatty acid composition of H’mong pumpkin seed oil exhibited the predominant of linoleic acid (53.24%) along with oleic acid (19.6%) and palmitic acid (16.73%). Total unsaturated fatty acid in oil was 73.52%. Therefore, the enzyme assisted aqueous extraction of H’mong pumpkin seed oil was an efficient extraction method which enhanced oil yield and quality of oil.