Investigation of the influence of minor components and fatty acid profile of oil on properties of beeswax and stearic acid-based oleogels.

Understanding the impact of minor components and the fatty acid profile of oil on oleogel properties is essential for optimizing their characteristics. Considering the scarcity of literature addressing this aspect, this study aimed to explore the correlation between these factors and the properties of beeswax and stearic acid-based oleogels derived from rice bran oil and sesame oil. Minor oil components were modified by stripping the oil, heating the oil with water, and adding ß-sitosterol. Oleogels were then prepared using a mixture of beeswax and stearic acid (3:1, w/w) at a concentration of 11.74 % (w/w). The properties of oils and oleogels were evaluated. The findings indicated that minor components and fatty acid composition of the oils substantially influence the oleogel properties. Removing minor components by stripping resulted in smaller and less uniformly distributed crystals and less oil binding capacity compared to the oleogels prepared from untreated oils. A moderate amount of minor components exhibited a significant influence on oleogel properties. The addition of ß-sitosterol did not show any influence on oleogel properties except for the oleogel made from untreated oil blend added with ß-sitosterol which had more uniform crystals in the microstructure and demonstrated better rheological stability when stored at 5 °C for two months. The oil composition did not show any influence on the thermal and molecular properties of oleogels. Consequently, the oleogel formulation derived from the untreated oil blend enriched with ß-sitosterol was identified as the optimal formula for subsequent development. The findings of this study suggest that the physical and mechanical properties as well as the oxidative stability of beeswax and stearic acid-based oleogels are significantly affected by the minor constituents and fatty acid composition of the oil. Moreover, it demonstrates that the properties of oleogels can be tailored by modifying oil composition by blending different oils.

Effect of Star Fruit (Averrhoa carambola L.)By-product on Oxidative Stability of Sesame (Sesamum indicum) Oil under Accelerated Oven Storage and during Frying.

Aim of this study was to evaluate the effect of star fruit (Averrhoa carambola L.) by-products (peel and residue) on stability of sesame (Sesamum indicum) oil against oxidation. Antioxidant properties of extract of peel and residue at different time durations of extraction were determined and found that peel contains higher antioxidant potential than residue. Thus, extract of peel obtained after 24 h extraction was used to study its effectiveness on oxidative stability of sesame oil during accelerated oven storage and frying using the butylated hydroxytoluene (BHT) (200 ppm) as the reference antioxidant (positive control) and oil without added antioxidant as the negative control. The oxidative stability of the oil was determined by evaluating peroxide value, p-anisidine value, thiobarbituric acid reactive substances (TBARS) value, total oxidation (TOTOX) value, conjugated diene (CD) and conjugated triene (CT) values, and iodine value. Peel extract at different concentrations (200-1000 ppm) was tested. The oil added with peel extract exhibited higher stability against oxidation than the controls during oven storage test. Extract at 1000 ppm significantly increased the stability of sesame oil during frying as compared with controls. Thus, star fruit peel extract could be an alternative to synthetic antioxidants to suppress oxidation of edible oils.