Effects of mangrove apple (Sonneratia caseolaris) fruit extract on oxidative stability of palm olein under accelerated storage

Palm olein is commonly used in cooking and food processing, however, it is susceptible to oxidation due to its high unsaturated fatty acids content. An antioxidant is added to the oil by oil manufacturer to inhibit lipid oxidation and increase the shelf life of the oil. However, most of the antioxidants are synthetic antioxidants that may not be safe for consumption and decomposed at high temperature during frying or processing. In this study, the antioxidant properties of mangrove apple fruit extract (MAFE), as well as the oxidative stability of palm olein with and without MAFE, were investigated. Palm olein added with MAFE (100 and 200 ppm) and without MAFE were kept at 65°C in an oven for 24 days under accelerated storage. The results showed that MAFE contained high total flavonoid compound (26.06±0.30 mg QCE/g extract) and total phenolic compound (12.21±1.31 mg GAE/g extract). The IC50 values of antioxidant activities of MAFE calculated by DPPH and ABTS•+ were 31.16±0.76 µg/mL and 97.32±3.27 µg/mL, respectively. The palm olein samples added with MAFE showed significantly lower peroxide value, p-anisidine value, TOTOX value, conjugated dienes and conjugated trienes after 24 days of storage compared to the palm olein without MAFE (control sample). The oxidative stability of palm olein added with 200 ppm MAFE was higher compared to the palm olein added with 100 ppm MAFE and control sample. Therefore, MAFE has the potential to be used as a source of natural antioxidant to reduce the lipid oxidation and prolong the shelf life of food products.