Oxidation Stability of O/W Emulsion Prepared with Linolenic Acid Enriched Diacylglycerol

The sn-1,3-regiospecific Rhizomucor miehei lipase (Lipozyme RM IM) was employed to produce structured diacylglycerol (SL-DAG), which contained 67.3 mol% DAG with 27.2 area% of C18:3. To investigate the oxidative stability of the SL-DAG in emulsion form, 5% oil-in-water (O/W) emulsions were prepared with 200 and 400 ppm sinapic acid. It was shown that the hydroperoxide values of the control (without any antioxidant) was the highest (117.7 meq/L) on day 43 of storage and thereafter the value decreased. However, the emulsions with 200 and 400 ppm sinapic acid resulted in slow oxidation degree until day 64 of storage (30.3 and 7.3 meq/L, respectively). Aldehyde measurements for the 200 ppm sinapic acid emulsion (12.8 mmol/mol) and the 400 ppm sinapic acid emulsion (7.5 mmol/mol) also showed better oxidative stability than that for the 200 ppm catechin emulsion (27.4 mmol/mol) and the control (52.7 mmol/mol). Although the SL-DAG in the emulsions contains high levels of polyunsaturated fatty acids, the degree of oxidation in the emulsions can be reduced when sinapic acid is used as an antioxidant. Practical Application In this study, structured diacylglycerol oil (SL-DAG) containing -linolenic acid (ALA) was enzymatically produced for the preparation of 5% O/W emulsion. Although the SL-DAG in the emulsions contains the high level of polyunsaturated fatty acids, the degree of lipid oxidation in the emulsions can be reduced when sinapic acid is used as an antioxidant. The results may help to expand the application of DAG oil enriched ALA for various purposes in food, cosmetic and living health industry.