Freezing of meat and aquatic food: Underlying mechanisms and implications on protein oxidation

Abstract

Over the recent decades,protein oxidation in muscle foods has gained increasing research interests as it is known that protein oxidation can affect eating quality and nutritional value of meat and aquatic products. Protein oxidation occurs during freezing/thawing and frozen storage of muscle foods, leading to irreversible physicochemical changes and impaired quality traits. Controlling oxidative damage to muscle foods during such technological processes requires a deeper understanding of the mechanisms of freezing-induced protein oxidation. This review focus on key physicochemical factors in freezing/thawing and frozen storage of muscle foods, such as formation of ice crystals, freeze concentrating and macromolecular crowding effect, instability of proteins at the icewater interface, freezer burn, lipid oxidation, and so on. Possible relationships between these physicochemical factors and protein oxidation are thoroughly discussed. In addition, the occurrence of protein oxidation, the impact on eating quality and nutrition, and controlling methods are also briefly reviewed. This review will shed light on the complicated mechanism of protein oxidation in frozen muscle foods.

Protein Oxidation in Muscle Foods: A Comprehensive Review

“…As commented, in addition to the health implications, it is evident that the modification of proteins due to oxidative degradation produces significant effects on the physico-chemical properties and functionality of food proteins [ 111 ], which change the foods quality [ 112 ]. However, the importance of protein oxidation on the deterioration of muscle food quality has only been partially investigated [ 2 ].…”

“…However, the importance of protein oxidation on the deterioration of muscle food quality has only been partially investigated [ 2 ]. Among all possible reactions, modifications of amino acid side chains such as thiol losses or the formation of carbonyls are the two most important changes that influence the quality of muscle foods [ 111 ]. In this sense, histidine was considered the main contributor of the increase in the formation of carbonyls [ 112 ].…”

“…Additionally, oxidative modifications also can lead to altered protein charges, which offer a new perspective to comprehend the mechanisms that protein oxidation generate on food quality [ 112 ]. Another important consequence of protein oxidation is the formation of protein cross-linking with covalent bonds within a protein or between proteins [ 2 , 111 ].…”

“…Among all physico-chemical properties of muscle foods, color, flavor, and texture are perhaps the most important attributes that determine, and affect, consumer acceptability [ 112 ]. Consequently, the microscopic changes that occur during protein oxidation could exert an enormous impact on the quality of muscle foods at the macroscopic level [ 111 ].…”

“…Generally speaking, it is accepted that oxidative reactions produce a negative effect on the texture of muscle foods by causing an increase in hardness and shear force values and a decrease in tenderness levels [ 88 , 111 ]. In this regard, the oxidative modification of proteins which implies the spatial arrangement, the formation of protein cross-linking, and the modification of protein net charges have a direct impact on the food texture [ 111 , 113 ].…”