Effects of carboxymethyl chitosan on the oxidation stability and gel properties of myofibrillar protein from frozen pork patties

The effect of carboxymethyl chitosan (CMCH) on the oxidation stability and gel properties of myofibrillar protein (MP) from frozen pork patties was investigated. The results showed that CMCH could inhibit the denaturation of MP induced by freezing. Compared with the control group, the protein solubility was significantly (P < 0.05) increased, while the carbonyl content, the loss of sulfhydryl groups, and the surface hydrophobicity were decreased, respectively. Meanwhile, the incorporation of CMCH could alleviate the influence of frozen storage on water mobility and reduce the water loss. With the increased concentration of CMCH, the whiteness, strength, and water-holding capacity (WHC) of MP gels were significantly improved, in which the maximum value was at addition level of 1 %. In addition, CMCH inhibited the decrease in the maximum elastic (G') value and loss factor (tan δ) value of samples. By scanning electron microscopy (SEM) observation, CMCH stabilized the microstructure of the gel and maintained the relative integrity of the gel tissue. These findings suggest that CMCH could be used as a cryoprotectant to maintain the structural stability of MP in pork patty during frozen storage.