Shelf life of Pacific white shrimp coated with gelatin extracted from Nile tilapia scales

Abstract

Gelatin coatings obtained from fish are a renewable technology with excellent benefits for the preservation of fish products and with high nutritional value, however, they are very perishable. This study evaluated the shelf life of Pacific white shrimp coated with gelatine extracted from Nile tilapia scales and glycerol, stored frozen at -18°C for 180 days. For this, the gelatin was extracted and applied at a concentration of 1.5% with 0.2% glycerol in peeled and headless shrimp (treatment G). This group was compared with uncoated shrimp (control – treatment C), peeled and headless, regarding psychrotrophic bacterial count (PBC), pH, total volatile bases nitrogen, trimethylamine nitrogen, and thiobarbituric acid-reactive substances every 30 days. As a result, the obtained gelatin extraction yield rate was 24.64% and the Total Bacterial Count (TBC) range for treatment C was 0.70 to 2.32 log CFU/g/estimated, while for treatment G was 0.70 to 1.48 log CFU/g/estimated. The shelf life evaluation showed that the gelatin-glycerol coating solution was effective in the preservation of P. vannamei in PBC, pH, TVB-N, TMA-N, and TBARS parameters. It was concluded that the use of this coating combined with frozen storage can be an excellent alternative to maintain the quality of Pacific white shrimp in the long term.