Oxysterols in food products

During the processing and storage of foods of animal origin, events that result in the formation of fatty acid radicals and hydroperoxides are also likely to lead to the formation of OS. The variables that are important in relation to fatty acid oxidation and OS formation in foods include composition of the food matrix, PUFA content and oxidizability, CHOL level, 

In an attempt to standardize the analysis of OS, a round-robin test on whole milk powder and skim-milk powder was organised by Appelqvist (1996). Analyses of OS were carried out in 17 laboratories and the differences in the level found led Appelqvist (1996) to conclude that it is still premature to establish true values for the level of OS in certain foods. The results of a second round-robin study on egg and milk powders showed that several OS in the samples were not determined or were below the determin- 

A number of review papers have been published recently on the formation and content of OS in eggs and egg products (Galobart and Guar-diola, 2002), milk and milk products (Stanton and Devery, 2002), meat and meat products (Kerry et al., 2002), sea-foods and sea-food products (Ohshima, 2002) and in other foods (Evangelisti and Zunin, 2002). Readers are encouraged to explore these reviews for information on the origin and content of OS in food systems. 

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