The Formation Of 4-Hydroxy-2-Trans-Nonenal (HNE), A Toxic Aldehyde, In Beef, Pork And Chicken Fats Heated At Frying Temperature (185°C)

University of Minnesota M.S. thesis. September 2017. Major: Food Science. Advisor: A. Saari Csallany. 1 computer file (PDF); xi, 121 pages4-Hydroxy-2-trans-nonenal (HNE), a secondary lipid oxidation product, is of special interest because of its abundance and toxicity. In this study, the HNE formation and secondary lipid oxidation of varies types of beef, pork and chicken fats undergoing heat treatment at 185°C frying temperature was investigated. Beef, pork and chicken fats were selected based on their different degrees of unsaturation and fatty acid distribution. Beef, pork and chicken fats from different sources were chosen to give comprehensive result. These fats were heated at 185°C for up to 6 hours. Lipid oxidation and secondary oxidation product formation of these fats were measured every hour by the thiobarbituric acid reactive substances (TBARS) assay. The formation of HNE in fats heated at 185°C for 0, 1, 3 and 5 hours were measured as 2,4-dinitrophnyhydrazone derivatives using HPLC system. The results show that 1) the formation of HNE and total secondary lipid oxidation products from all fat sources were increased with the heating time; 2) HNE formation and total secondary lipid oxidation products levels in beef, pork and chicken fats are correlated with their linoleic acid and PUFA percentage, respectively; 3) the HNE formation and total secondary lipid oxidation products of fat extracted from ground meats were lower than that from fat tissues, this may be related to antioxidants content in the meat. Overall, beef fats produce less HNE and total secondary lipid oxidation products under thermal treatment, compared to pork and chicken fats as well as most vegetable oils