Tropical oil blending and their effects on nutritional content and physicochemical properties during deep fat frying

Abstract

Oil blending is a method that may improve the nutritional profile and stability of frying oil. Tropical vegetable oils, including rice bran oil, coconut oil, and palm oil were blended at ratios of 20: 20: 60, 25: 25: 50, 30: 30: 40, and 35: 35: 30 (v/v/v), respec-tively, and tested for their performance in deep frying French fries at 180˚C for 8 h. The nutritional content of the blended oils increased with the rice bran oil and coconut oil ratio, including polyunsaturated fatty acids, α-tocopherol and γ-oryzanol. The physicochemical property changes, including color, viscosity, fatty acid profile, total polar compounds, free fatty acid, peroxide value, and the thiobarbituric acid reactive substances value of the blended oils were monitored during frying. The lightness of the oil blends was higher than those of palm oil after frying. However, the higher ratio of rice bran oil and coconut oil resulted in a higher increase in viscosity during frying. The oxidative stabilities of the oil blends were better than that of palm oil. Additionally, the sensory characteristics of the fries prepared in these oil blends were evaluated using a 9-point hedonic scale. There was no significant difference in sensory attributes of the fries produced using different oils. The oil blended at a ratio of 30: 30: 40 shows the greatest performance as a deep frying media compared to the other blended oils that were tested.