Using rice bran as a press aid during the cold-pressing of sesame seeds improved the extraction yield and quality of the resultant oil.

Abstract

Simple, cost-effective, and practical techniques can enhance the shelf life of cold-pressed oils. This study evaluated sesame seed (SS) cold-pressed oil with various percentages of rice bran (RB) as press aid, including 0% (control or TSSO), 1% (T1), 2.5% (T2.5), 5% (T5), 7.5% (T7.5), and 10% (T10) w/w. The results demonstrated that adding RB considerably boosted extraction yields (p < .05), with 5% RB constituting the ideal combination. Adding 7.5% and 10% RB to the SS reduced free fatty acid (FFA) levels compared to the control sample. The oxidative stability index (OSI) and peroxide value (PV), however, significantly increased at combination ratios ranging from 2.5% to 10% (p < .05). Rice bran oil (TRBO) had the greatest OSI of all the studied oils, with 18.99 h, while the extracted oils showed an increase in OSI as RB contents rose. Total phenolic compounds (TPC), tocopherols, γ-oryzanol content, and total antioxidant activity (TAA) increased directly with the RB level. Despite the addition of RB altering the fatty acids concentration, linoleic and oleic acids continued to be the predominant fatty acids in TSSO, TRBO, and other extracted oil samples. Increasing the combination ratio increased the palmitic, palmitoleic, oleic, and linolenic acid content and decreased the stearic and linoleic acid content. In summary, the study demonstrated that the simultaneous cold-pressing of oil-bearing seeds and agro-industrial by-products is a potentially advantageous technique to increase the extraction yield, qualitative attributes, and shelf life of the extracted oils without the addition of synthetic antioxidants.