Effect of high pressure shucking on the gel properties and in vitro digestibility of myofibrillar proteins from red swamp crayfish (Procambarus clarkii)

Abstract

The effect of high pressure shucking (HPS) on heat-induced gelation properties of myofibrillar proteins from shucked crayfish meat mince was investigated, by comparing with conventionally industrial shucking methods (i.e., freeze-thawing and cooking). The texture, color, water holding capacity, water distribution, microstructure, protein patterns and secondary structure as well as the pepsin digestibility and antioxidant activity of gels were evaluated. Compared to conventional shucking, HPS at 300 MPa resulted in good-quality gels with improved mechanical properties and desirable reddish color. The treatment seemed to be conducive to the maintenance of astaxanthin, although it slightly reduced the water holding capacity and proportion of T22 water. SEM analysis showed that the gels treated by HPS at 300 MPa had a more orderly and uniform microstructure with reduced pore size. Under this scenario, more myosin heavy chains appeared to be involved in the crosslinking as revealed by SDS-PAGE. However, FTIR results suggested that no obvious change was found in the protein secondary structure of gels. Intriguingly, HPS of 300 MPa enhanced the pepsin digestibility and ABTS-radical scavenging activity of the gels during in vitro digestion. These findings underlined the advantages of HPS for creating new gel-type products based on crayfish meat.