Aerobic-liquor treatment improves the quality and deep-frying performance of refined palm oil

Abstract

Deep-frying is a popular method for food preparation because it improves the taste and sensory of food. Among the vegetable oils, palm oil is one of the commonly used oils for deep-frying application. During deep-frying, some of the oil would be absorbed by the food and subsequently be consumed together with the food. Hence, the quality and stability of the oil used for deep-frying are of critical food safety considerations. To address this issue, we produced refined palm oil from crude palm oil which has been treated with an aerobic liquor (AL) generated from a palm oil mill. The result shows that the refined palm oil produced from AL-treated CPO (aRPO) has improved quality, in particular the 3-monochloropropane-1,2 diol ester (3-MCPDE) and the glycidyl ester (GE) reduced by 58% and 46%, respectively. After 30 cycles of deep-frying, the used aRPO contained 68% lower FFA content, 13% lower polar content, and 43% lower 3-MCPDE content compared to the conventionally produced refined palm oil (RPO). Furthermore, the aRPO has a higher smoke-point and a higher resistance to darkening compared to the RPO. As a result, the fries prepared using aRPO have lower 3-MCPDE content and they have a better appearance and were less greasy when compared to the fries prepared using RPO. Overall, AL-treatment of CPO is a feasible method to improve the quality and deep-frying performance of refined palm oil and it could readily be adopted by the industry because it is simple and sustainable.