Protective Role of Bio-Based Coating of Ultrasound-Improved Trout (Oncorhynchus mykiss Walbaum, 1792) Waste Protein Hydrolysate for Bonito (Sarda sarda Bloch, 1793) Fillets at Storage at -18±1°C

A novel and rich protein source was utilized in bonito fillets to prevent/ delay deterioration during frozen storage at -18±1°C. Accordingly, trout wastes hydrolysates (PH); produced enzymatically traditional hydrolysate (TPH) ultrasound–treated (UPH) containing 86.40 g/100 g 86.75 respectively used as a coating. Hydrolysates were mixed with glycerol (2:1) form coating materials. Three groups of prepared control (C) without coating, TPH coated (TPHCF), UPH (UPHCF). pH, color, TVB-N, TBA, TMA, sensory analyzes performed all groups. The L* value reached maximum the highest 6 months 54.56±0.27, 53.74±0.23, 54.83±1.26 for C, TPHCF, UPHCF, respectively. TVB-N 18.08±0.10, 17.71±0.09, 17.36±0.12, respectively, first month storage. values 32.18±0.29, 26.61±0.12, 25.72±0.08 7th TBA C group samples 7.53 month, it remained within consumable limits, limits Significant increases occurred TMA between seven-month period. UPHCF 2.56±0.04 mg/100 g, 2.12±0.04mg/100 2.16±0.06mg/100 month. mean parameters 9.15±0.08; 9.51±0.12 9.46±0.13 1st While they 5.29±0.09, 6.23±0.06 6.24±0.09, THE same order, Results showed that TPHCF have potential conditions, prolonging shelf life.