Study of Structured Lipid-Based Oil-in-Water Emulsion Prepared with Sophorolipid and its Oxidative Stability

In this study, the stability of oil-in-water (O/W) emulsions prepared with structured lipid (SL) were evaluated in which the SL was produced through lipase-catalyzed interesterification between soybean oil and rice bran oil. After interesterification, the major TAG species in the SL were PLP (22.5 %), PLL/OOLn (21.8 %), LPL (16.1 %), and LLS/PLO (16.1 %), and the total amount of tocopherol and tocotrienol was 20.9 mg/100 g of SL. Sophorolipid was used as an emulsifier for preparing SL-based O/W emulsions, and the effect of pH (pH 5.8, 7 and 7.2) on stability was studied by analyzing the fat globule size. From the results, SL-based O/W emulsions showed similar stabilities to those prepared with Tween 20 at the neutral environment. In the oxidation study, any antioxidant addition of propyl gallate (PG), ascorbic acid 6-palmitate (AP) or quercetin hydrate (Que) distinctively prevented peroxide formation on the SL-based O/W emulsion throughout the 23 days of storage while AP was less effective to lower TBARS values than PG and Que.