Frying oils selection

Fig. 34. 3. Structures of selected sterols. Sources animal - lanosterol, cholesterol and ergosterol (also microbial) plant - all others. (From Warner, K., Su, C, and White, P.J. "Role of Antioxidants and Polymerization Inhibitors in Protecting Frying Oils" in Frying Technology and Practices, M.K. Gupta, K. Warner, and P.J. White (Eds.), pp. 37-49, AOCS Press, Champaign, IL 2004. With permission.)...

Industrial fryers generally are of two types (1) those who sell all the purchased oil with the product, and (2) those who must recondition and occasionally dispose of oil. Requirements for the selection and use of frying oils in these applications differ.175 Industrial snack food fryers, designed to use all the oil, are equipped with clean-out systems and inline filters. In theory, they should be able to operate indefinitely, only adding make-up oil as needed. In clean label, operations, company policy dictates that no, or minimum, additives can be used. Typically, company personnel periodically inspect and... 

Frying oil has been available to man in various parts of the world. Most of the time a specific oil has been selected for frying because it is locally available. Man also has moved from the crude expelled oils to refined oils as the oil technology advanced. In addition, the availability of most oils across the world has also increased due to improved transportation and storage systems developed over the years. Consumers have been exposed to the taste of products fried in different types of oil for quite sometime. Production of other than the indigenous oils has also become common where the local climate, soil conditions, and overall agronomy have been favorable to a particular type of oilseed or oil palm trees. 

Takeoka GR, Full GH, Dao LT (1997) Effect of heating on the characteristics and chemical composition of selected frying oils and fats. J Agric Food Chem 45 3244-3249 Tamer IM, Murray MY, Chisti Y (1998) Optimization of poly(p-hydroxybutyric acid) recovery from Alcaligenes latus combined mechanical and chemical treatments. Biopioc Biosyst Eng 19 459-468... 

Abidi, S. L. and Warner, K. Molecular-weight distribution of degradation products in selected frying oils. J. Am. Oil Chem. Soc. 78, 763-769 (2001). 

The following criteria (2) are applied for the selection of oil for industrial frying ... 

These two functions are the key to selecting the proper shortening for a given application. Also, the fatty acids in the oil fraction are generally more unsaturated than those in the solid part, and polyunsaturated fatty acids are subject to the development of oxidative rancidity. Oxidative stability is especially important in shortenings that are exposed to air (cracker spray oils) and high temperatures (frying fats). 

Simonne, A.H. and EitenmiUer, R.R. 1998. Retention of Vitamin E and Added Retinyl Palmitate in Selected Vegetable Oils during Deep-Fat Frying and in Fried Breaded Products. J. Agric. Food Chem. 46 5273-5277. 

Trans isomers always occur in oil-fried products because they are formed at high temperatures. The developments in fat hydrogenation with respect to process optinuzation and the selection of catalysts have resulted in a gradual reduction in FA trans isomers in partially hydrogenated fats. The result of complete hydrogenation, in which all bonds of unsaturated FA are saturated with hydrogen, are hardened fats that undergo further modification by interesterification. 

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