Influence of Fractionation on the Oxidative Stability, Thermal Stability, and Fatty Acid Profile of Shea Olein Fractions

Abstract

Oxidative stability can directly affect oil quality and shelf life, especially in fat and oil-containing products such as shea olein. Shea butter is becoming increasingly popular in foods, cosmetics and pharmaceutical products, but is generally unstable. The fractionation of shea butter affects the stability of shea olein. Therefore, this study investigated the effect of fractionalization on oxidative and thermal stability with fatty acid composition of shea olein. Shea butter was fractionalized using a cold centrifuge at 5 ? and -5 ? to obtain two fractions of shea olein. The stability of the shea olein fractions was evaluated with peroxide values (PV), p-anisidine value (p-AV), conjugated dienes (CD), and Thiobarbituric Acid Reactive Substances (TBARS). The thermal stability and fatty acid composition were determined using the differential scanning calorimetry method and the Gas Chromatographic method. The percentage yield for crude shea butter, shea olein (DSOA), and super shea olein (DSOB) were 37.5%, 75.59% and 50.94%, respectively. The PV, p-AV, CD and TBARS were in the ranges 0.32-1.59 meq O/kg, 7.28 - 11.51, 0.59 - 5.00 mmol/g and 0.10 to 0.14 mmol/g. The thermal stability reflects an endothermic transition of CSB, DSOA, and DSOB as -17.35 mW, -12.93 mW, and -3.85 mW, while their fatty acid profile revealed two prominent acids, arachidic acid (39.87, 40.04, and 29.26%), oleic acid (47.83%, 48.30%, and 56.23%), respectively. The study demonstrated that the oxidative and thermal stability of shea olein is achievable during fractionation, leading to a more stable oil for food formulations.