Fatty acid frying stability

Com oil s flavor, color, stability, retained clarity at refrigerator temperatures, polyunsaturated fatty acid composition, and vitamin E content make it a premium vegetable oil. The major uses are frying or salad applications (50%) and margarine formulations (35%). 

If that does occur, then the present system of classification of oils may be impossible to police, and a modified system may become necessary. Perhaps the sale and perceived value of oils will necessarily become dependent on the performance, not the source of the oil. With bulk oils such as palm, peanut, sunflower, safflower, sesame, soya, rapeseed, com, fish, and animal fats and oils, the fatty acid composition will obviously be important for health reasons. If the oil is to be used for frying then the frying properties will be important. In the case of palm products the physical properties and minor components such as carotenoids will be defined. Similarly animal fats will be judged mainly on physical behaviour and effect on the product in which they are used. In all cases the oxidative and stability of the oil will have to be defined. Sesame is a very stable oil, and thus its stability, together with its low level of linolenic acid, would be its major attribute, except for toasted sesame, which would probably be classed as a specialist oil. Already most baking fats sold to the public are blends developed to give the best performance, with no mention on the pack as to the source. If a bulk oil of this type had the desired chemical composition, stability and cooking behaviour, then perhaps the source would not be a matter of concern. 

Frying Fats Large amounts of canola oil are used as lightly hydrogenated (IV 90), stable, but pourable frying fat. Canola oil is uniquely suited to combine good stability with pourability because of its fatty acid composition. 

Oil Source Fatty Acid Composition, % Inherent Oxidative Stability Fried Flavor... 

Some palm oil processing companies in Malaysia are producing and exporting fully processed palm oil and palm olein with low free fatty acids, diacylglycerols, phosphorus, and trace metals. They guarantee the delivered quality for the oil. These oils have shown excellent frying stability. 

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). 

Phospholipids, if not removed from oils before deodorization, can lead to dark-colored oils and serve as off-flavor precursors (53, 54). Chlorophyll (55), pheophytins and pyropheophytins (56), and metal ions (57, 58) are prooxidants that decrease oil stability. Iron and copper at levels as low as 0.01 and 0.1 ppm, respectively, are capable of lowering flavor and oxidative stabihty (59). Free fatty acids, besides representing a refining loss, have also been shown to act as prooxidants (60) and to lower smoke points (61) of oils during frying. Uinolenic acid has... 

Warner, K. and Mounts, T.L. (1993) Frying stability of soybean and canola oils with modified fatty acid... 

---