Study on a novel vacuum sublimation-rehydration thawing method for large yellow croaker (Larimichthys crocea) and...

To address the issues of high energy consumption, fish body damage, and nutrient loss during the thawing of frozen large yellow croaker, a novel vacuum sublimation-rehydration thawing (VSRT) method, previously proposed by our group, was applied to frozen large yellow croaker. The effectiveness of this method and the influence of sublimation time, one of its key operating parameters, were investigated. To avoid judging the process from a single indicator, sublimation time was evaluated using thawing efficiency, thawing quality, and system-specific energy consumption. The results indicated that, under the fixed heating-plate and rehydration-vapor conditions used in this study, sublimation time had a non-monotonic effect on thawing performance. Based on a weighted multi-index evaluation, 10 min was selected as the preferred sublimation time. Under this condition, the total thawing time was relatively short (128.1 min), the thawing loss was low (1.35%), and the post-thaw quality was close to that of chilled large yellow croaker. A comparative analysis was also conducted among VSRT, vacuum-steam thawing (VST), running-water thawing, and natural air thawing (NAT). The results showed that the thawing time of VSRT was comparable to that of running-water thawing and 36.2% shorter than that of VST. Moreover, the system-specific energy consumption was reduced by 76.2% compared with VST, while muscle hardness, adhesiveness, and cohesiveness showed no significant differences from those of chilled large yellow croaker. This study provides a new technical route for improving the efficiency and quality retention of large yellow croaker thawing.