Effect of high-pressure processing on polyphenol oxidase, melanosis and quality in ready-to-eat crabs during storage

High-pressure processing (HPP: 300MPa, 5 min) was applied to ready-to-eat (RTE) crab treatment, and the melanosis and quality changes were monitored during storage at 4 degrees C. The results showed that HPP caused changes in the relative molecular mass of polyphenol oxidase (PPO) protein, which resulted in the decrease of PPO activity by more than 50%, thus delaying the blackening. RTE crabs with the application of HPP showed less damage to muscle tissues during storage, with fibers appearing fused and more compact compared to the control samples. At the end of storage, the marinade pH of HPP-treated samples was significantly reduced by 34.92% compared to control samples, which may also account for the lower degree of lipid oxidation. HPP could significantly inhibit the formation of biogenic amine precursors-related free amino acids and reduce taste-related free amino acids formation. The increased springiness of leg meat was found in HPP-treated samples, with respect to the control samples. Microbiological assessment showed a shelf-life of 15 days for unpressurized samples and 31 days for HPP-treated samples, demonstrating the high potential of HPP against microbial. HHP-treated samples had better sensory attributes than the control samples.