Oxidative stabilities of mango kernel fat fractions produced by three-stage fractionation

Trans-free mango kernel fat stearins and oleins were produced by three-stage acetone fractionation to achieve the sufficient utilization of fat. Fatty acid and triacylglycerol compositions, slip melting points, iodine values, micronutrient (tocopherol, sterol, and squalene) levels, as well as oxidative stability indexes of the fractions were analyzed to evaluate their qualities. The most abundant fatty acids in the stearins were saturated fatty acids (57.3–65.1%, mainly including palmitic, stearic, and arachidic acids), and the major triacylglycerols were symmetrical monounsaturated types (78.3–93.7%). The unique properties make the stearins show highest slip melting points 34.7–38.3°C and oxidative stability indexes (12.0–14.2 h), and very suitable for the manufacturing of hard chocolate fats. The oleins contained high percentages of monounsaturated (48.3–53.7%) and polyunsaturated fatty acids (7.8–8.5%). Their oxidative stability indexes (6.3–6.7 h) were lower than the stearins but higher than common commercial oils. About 85.2% of tocopherol, 99.2% of sterol, and 79.2% of squalene were transferred to the liquids after fractionation, which could improve their antioxidant abilities. Further multiple linear regression analyses between oxidative stability indexes and fat compositions revealed that polyunsaturated fatty acid and sterol were the main factors that affect the oxidative stabilities of the fractions. The results suggested that the moderated refining techniques should be developed to retain more sterol to improve the oxidative stabilities and nutritive values of the fats.