Effect of vacuum packaging on the quality of red claw crayfish, Cherax quadricarinatus, tail muscle during frozen storage.

This study compared vacuum packaging (VP) and air-permeable polyvinylchloride film wrap packaging (PVCP) for their influence on microbial survival, pH, protein physicochemical properties, cooking loss, and shear force of raw red claw crayfish, Cherax quadricarinatus, tail muscle stored at −20 C for up to 12 mo. Overall, frozen storage did not have a detrimental effect on microbial survival; however, aerobic plate counts and total coliforms in 12-mo red claw samples in VP were, respectively, 1.5 and 3.1 log cycles less than those in PVCP (P < 0.05). Samples stored in both PV and PVCP exhibited a slight pH decline (0.3–0.5 U, P < 0.05) during storage. Similarly, the complex changes in muscle proteins over the course of frozen storage, for example, increases in hydrophobicity in the first 3 mo, reductions of Ca-ATPase activity from 3 to 12 mo, and loss of sulfhydryls from 6 to 12 mo (P < 0.05), differed only slightly between VP and PVCP. Muscle samples stored in PVCP experienced a significant cooking loss after 1 mo, and in VP, a major cooking loss occurred after 3 mo. No packaging effect was observed on cooked meat shear force except for samples stored for 12 mo.