Research Accomplishment Reports 2007

Mechanism of Oxidation-Induced Functionally Changes of Myofibrillar Protein

Y.L. Xiong, A.L. Alderton
Department of Animal and Food Sciences

 

Project Description

Oxygen radicals are produced naturally during meat processing and storage, and are known to affect the functional properties of proteins responsible for the textural attributes of muscle foods, for example, gelation, emulsification and water binding. The exposure of meat myofibrillar protein to low concentrations of hydroxyl radicals and oxidizing metmyoglobin resulted in an improved elasticity (by up to 36%) of the protein gel network formed upon cooking, which was attributed to enhanced aggregation of myosin through tail-tail interactions. This improvement was inhibited when an antioxidative potato protein hydrolysate was present. However, oxidation lowered protein emulsifying capacity and water-binding ability. The study provides the first evidence that mild oxidation can facilitate muscle protein gelation, a property that is critical to cohesiveness and firmness of comminuted muscle foods.

Impact

This study offered an insight into the oxidation-induced alteration in the function of pork myofibrillar protein. Through understanding that mild oxidative modification under a typical meat processing salt and pH condition promotes myosin tail cross-linking and gel network formation, meat processors may be able to manipulate ingredient and processing options to allow limited oxidation to produce comminuted meat products with an array of firmness, elasticity and mouthfeel.

Publications

Park, D., Xiong, Y.L., and Alderton, A.L. (2007). Concentration effects of hydroxyl radical oxidizing systems on biochemical properties of porcine muscle myofibrillar protein. Food Chemistry, 101:1239-1246.

Park, D. and Xiong, Y.L. (2007). Oxidative modification of amino acids in porcine myofibrillar protein isolates exposed to three oxidizing systems. Food Chemistry, 103:607-616.

Xiong, Y.L. and Blanchard, S.P. (2007). Promotion of gel network formation of myofibrillar proteins through controlled oxidative modification of protein aggregation. Book of Abstracts. Annual Meeting of the Institute of Food Technologists. Abst. No. 184-03.

Wang, L.L. and Xiong, Y.L. (2007). Antioxidative potato protein hydrolysate reduces biochemical changes in myofibrillar proteins exposed to oxidizing compounds. Book of Abstracts. Annual Meeting of the Institute of Food Technologists. (Abst. No. 094-16).

Blanchard, S.P., Chen, J., Park, D., Ma, Y., and Xiong, Y.L. (2007). The Fe-H2O2 oxidation promotes myofibrillar protein gelation by enhancing myosin tail-tail interaction. Proceedings of 53nd International Congress of Meat Sciences and Technology (ICoMST), 53, 159-160.