Effect of high pressure processing on the physicochemical and sensorial properties of scallop ( Mizuhopecten yessoensis ) during iced storage

Effect of ultra-high pressure on the relationship between endogenous proteases and protein degradation of Yesso scallop (Mizuhopecten yessoensis) adductor muscle during iced storage

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UHP treatment slowed down the texture deterioration during iced storage.

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UHP treatment reduced protein degradation and oxidation.

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Endogenous enzyme activity was closely related to protein degradation and denaturation.

This study aimed to explore the effect of ultra-high pressure (UHP) treatment (100–500 MPa, 5 min, 15 ± 1 ℃) on the relationship between endogenous proteases and protein degradation of Yesso scallop (Mizuhopecten yessoensis) adductor muscle during iced storage for 28 days. Our findings showed that the UHP treatment kept the water holding capacity stable, increased the hardness and decreased the springiness of scallop adductor muscle during iced storage. 400 and 500 MPa UHP treatments caused protein denaturation and oxidation significantly, decreased protein degradation rate and inhibited the activities of endogenous proteases. According to the correlation analysis, the activities of cathepsin B, D, H, L, calpain and serine protease were positively correlated with TCA-soluble peptides. The activities of endogenous proteases were significantly correlated with protein degradation. Therefore, the effect of UHP on endogenous protease caused the protein degradation rate to slow down and prevented the texture deterioration in scallops.

Shrimp ( Penaeus monodon ) preservation by using chitosan and tea polyphenol coating combined with high‐pressure processing

The present work investigated the effects of high‐pressure processing (200 and 400 MPa, 5 min) combined with chitosan‐tea polyphenol (1.5% and 0.5% [w/v], respectively) coating to improve the quality and stability of shrimp (Penaeus monodon) during 28 days of storage. The chemical (pH, TVB‐N, TBARS), microbiological, textural, chromatic characteristics, protein oxidation, and endogenous enzyme activities of shrimps were regularly evaluated. Results showed that the combination treatment exerted a better intense antimicrobial effect, stabilized shrimp's freshness, and resulted in lower pH and TVB‐N than the control sample. Also, combined treated samples had better oxidative stability than a single treatment until the end of shelf life. Although combination treatment had no significant effect on endogenous proteases, the combined use of 400 MPa high‐pressure and chitosan‐tea polyphenol coating was most effective in inhibiting the bacteria and improved the hardness and chromatic characteristics of shrimp within the storage.