Myofibrillar protein denaturation/oxidation in freezing-thawing impair the heat-induced gelation: Mechanisms and control technologies

Freezing has been widely used to preserve meat and aquatic products. However, environmental fluctuations in freezing/thawing would bring inevitable damage to the structure and characteristics of myofibrillar proteins. The gelation of myofibrillar proteins during thermal processing significantly impacts the quality of gel-type muscle foods. Therefore, it is of critical importance to understand role of freezing-induced damage to myofibrillar proteins in heat-induced gelation. This review covers recent developments on quality changes of myofibrillar protein gels in relation to freezing/thawing and presents the mechanisms and the control technologies available for improving gelling properties of frozen-thawed myofibrillar proteins. The mechanisms are based on the denaturation and oxidation of myofibrillar proteins occurring in freezing/thawing and the relationship with molecular aggregation during gelation. The emerging technologies discussed herein focus on freezing/thawing technologies and applications of cryoprotectants. The degree of myofibrillar protein cross-linking in relation to denaturation and oxidation plays a crucial role in further molecular aggregation during gelation. We here propose that freezing-induced over-aggregation of myofibrillar proteins in relation to denaturation and oxidation would spatially hinder salt dissolution and further intermolecular assembling of myosin during gelation, thus producing an amorphous gel network. Recent novel technologies preserve myofibrillar protein characteristics from freezing-induced denaturation and oxidation by accelerating freezing/thawing rate and inhibiting ice crystal growth and therefore modify gelling properties of frozen-thawed myofibrillar proteins. This review could be helpful for the development of gel-type muscle foods processed from frozen-thawed meat and aquatic products as raw materials.