Protein oxidation in muscle-based products: Effects on physicochemical properties, quality concerns, and challenges to food industry.

Protein oxidation in meat has received immense attention since it significantly affects the quality of meat-based products. This review sheds light on the effects of protein oxidation on the physicochemical properties of meat and meat-based products during processing, and highlights major quality concerns and challenges to the food industry. Protein oxidation is often initiated by oxidative attack by reactive oxygen species and modifications of side chain amino acids, which may result in protein aggregation, carbonylation, alteration of surface hydrophobicity, and perturbation in primary, secondary and tertiary structures. Thus, protein oxidation during processing (especially thermal treatments) has raised serious concerns about the quality of the final products. These adverse consequences usually intensify with increase in processing temperature and time. Protein oxidation may also cause severe deterioration of nutritional value owing to the loss of essential amino acids and resistance of the oxidized protein molecules to the hydrolytic action of digestive enzymes. In addition, it may promote drip loss and decrease water holding capacity that would eventually negatively impact texture. Furthermore, protein oxidation is closely associated with other processing-induced adverse events, in particular lipid oxidation and formation of toxic Maillard reaction products, such as heterocyclic amines and advanced glycation end-products, but the underlying mechanisms have remained unclear. Several strategies including careful choice of processing methods and use of natural agents, such as polyphenols, hydrocolloids and vitamins alone or in combination have been proposed for the attenuation of protein oxidation and its related undesirable reactions through binding with precursors and/or reactive intermediary compounds.