Role of Minor Constituents and Balanced Fatty Acids in Upgrading the Low Stability of Cooking Oils Blended with Palm Super Olein

摘要

Background: Vegetable oil blending is one of the most potent ways in improving and upgrading low stability cooking oils. Objective: This study is chiefly concerned by the balance between saturated, monounsaturated and polyunsaturated fatty acids as recommended by World Health Organization (WHO) as well as improving their oxidative stability. Methodology: Palm super olein was blended with soybean and sunflower oils at different ratios, namely, 50:50, 55:45, 60:40, 65:35 and 75:25% w/w to identify the best cooking oil blends in terms of fatty acid balance and other specific characteristics. Bioactive minor lipid constituents of cooking oils and their blends including vitamin E, phytosterols, phytostanols, fatty acid components and oxidative stability were analyzed. Results: The 50:50 and 55:45% super palm olein:soybean or sunflower oil blend show the highest content of total tocopherols. While, the ratio of 65 and 75% of palm super olein blends to other oils, gave the highest amount of total tocotrienol which is the most potent antioxidants. With reference to phytosterols composition, it was found that the ratio 50:50 and 55:45% super palm olein:sunflower oil blend show highest amount of 5-, 7-stigmasterol, β-sitosterol, 7-avenasterol. While, the highest level of 5-stigmasterol and β-sitosterol was found in the blend of palm olein:soybean (50:50 and 55:45%). Most of phytosterols components exert antioxidant effects and enhance immunity in the human body. The ratio 55, 60 and 65% of palm super olein to soybean or sunflower oils show nearly ideal proportion between fatty acid groups. Conclusion: The addition of palm super olein to sunflower and soybean oils improves the oxidative stability of these oil blends and increases their phytonutrient contents as well as the nutritional value of oil blends via the balance between fatty acids.