Research on extraction technology to improve yield and quality of oil from gac aril (Momordica cochinchinensis Spreng L.)
Abstract
Gac aril has an oil content of about 38% - 40% (as related to absolute dry matter). This oil is a rich source of beta-caroten and lycopen, containing 128 mg%, and 170 mg% of each, respectively. The alpha-tocopherol content in the pulp was found to be 76.3 µg/g. Because of its valuable constituents as mentioned above, Gac fruit oil is studied and used to create functional food and pharmaceutical products. Currently, Gac aril oil production is mainly carried out by traditional mechanical expression with a screw press, but this method gives low yield and quality (especially in regard to the content of beta-caroten and lycopen). This paper describes a new method to obtain Gac aril oil with high extraction yield and oil quality. The advantage of n-hexane solvent extraction in theproduction of Gac aril oil as compared to conventional pressing is an increased oil yield (96.4%, compared with 72.5% as by traditional screw pressing). The obtaining oil yield and the content of beta-carotene in Gac aril oil product from extraction were 96.4% and 320 mg% respectively, which were significantly higher than those from mechanical expression (72.5% and 193 mg%). The acid and peroxide value of Gac aril oil were found to be 4.8 mgKOH/g and 5.4 meqO 2/kg, respectively.