Evaluation of the Quality of Pacific White Shrimp Under Different Storage Conditions

This study focused on the inhibition of melanosis formation, shelf-life extension, and the correlation between quality indices under different treatment conditions during the storage of Pacific white shrimp at 0 °C. The treatment groups included: a control sample, samples treated with 0.5% benzaldehyde solution, samples treated with 2% chitosan solution, and samples treated with a combination of 0.5% benzaldehyde and 2% chitosan. Sensory, chemical, and microbiological evaluation methods were applied using quality indicators such as melanosis score, TVB-N, TMA-N, hypoxanthine, and TVC. TVC results demonstrated that the antibacterial and antioxidant properties of benzaldehyde and chitosan extended the shelf life to 12 days (benzaldehyde), 11 days (chitosan), and 15 days (benzaldehyde/chitosan), compared to 8 days for the control. The formation of a Schiff base from the reaction between benzaldehyde and tyrosine was shown to inhibit tyrosinase activity, thereby reducing melanosis. The benzaldehyde and benzaldehyde/chitosan samples maintained acceptable melanosis scores (≤ 6) up to days 12 and 15, respectively, compared to days 8 and 11 for the control and chitosan samples. Changes in TVB-N and TMA-N were analyzed across two stages, autolysis and decomposition, allowing for the development of linear regression equations with high correlation coefficients (R² ≈ 0.99). Similar linear trends were observed for melanosis and hypoxanthine. The study established strong linear correlations between melanosis score, TVB-N, TMA-N, and hypoxanthine across all treatment groups, providing a foundation for predictive modelling of shrimp quality under different preservation conditions.