Thermal degradation studies on Edible oils during Deep Fat Frying Process

Abstract

Deep fat frying process is one of the widely followed cooking practices throughout the newlineworld. Cooking oils serve as a medium for frying food for transferring heat and makes fried newlinefood tasty and palatable. Frying process is a most complex process involving numerous newlinephysicochemical changes which are complicated to understand. Frying leads to thermal newlinedegradation of oil through thermo-oxidation, hydrolysis, and polymerization. Hydrolysis newlineresults in formation of free fatty acids whereas oxidation process produces hydroperoxides newlineand small molecular carbonyl compounds. This whole process leads to the formation of polar newlinecompounds and degradation of antioxidants that further degrades frying oil. Eventually, newlinethrough mass transfer process these degradation products accumulate into fried food and newlinereduce the nutritional quality of both oil and food. Thus, the frying process is of research newlineinterest calls for detailed systematic study which is chosen for the present study. The primary newlineobjective of this study is to understand the mechanism of degradation and characterization of newlinedegraded products which helps in arriving at the limits for frying oil utilization in terms of newlinenumber of frying cycles. The mechanistic studies and the knowledge on the degraded newlineproducts help to understand the way to retard the deterioration of oil for stability and newlineenhancement of frying cycles. The study also explores the formation of the predominant newlinepolar compounds and their structural elucidation through mass spectrometry. Oxidation of oil newlineis another important factor that ignites the degradation phenomena. One of the best ways to newlineincrease thermal stability of any oil is addition of potent antioxidants. But, most of the natural newlineand synthetic antioxidants are unstable and ineffective at frying temperatures. Therefore, it is newlinenecessary to screen alternative antioxidants for their activity in the refined oils which are devoid of any added antioxidants. In this context, this study discussed the efficacy of several newlinenatural and synthetic antioxidants to retard the formation of polar compounds and thermooxidation newlineduring prolonged frying conditions. Similarly, the advantage of blending of two newlinedifferent oils to improve the thermal stability was explored. The present study brings out the newlinetotal picture on the type of degradation products formed during frying and the ways of newlineretarding the determination to improve upon the stability of the oil and enhancement of frying newlinecycles newline