Processing and Products

The scarcity of conventional feed resources and their high price has necessitated exploring cost effective non-conventional ingredients to be utilized to replace the conventional ones like hatchery waste (HW). The chemical composition of HW has revealed its nutrient composition especially higher level of fat (1821%), which pose threat to spoil the quality of of product through rancidity. Hatchery waste was processed by simple cooking, autoclaving, extrusion cooking. Four different levels of antioxidant (Oxygun) at 0, 100, 200 and 300 mg/kg were added to all the processed and raw hatchery waste. The samples were stored for 50 d and analyzed for peroxide value (PV), thiobarbituric acid value (TBA) and free fatty acids (FFA) contents with the interval of 10 d to evaluate the fat storage stability of HW. There was a linear increase in PV, FFA and TBA values of all the treatments throughout the storage period. Comparison within the raw hatchery waste and processed HW revealed that extrusion cooking was the most effective processing technique to check fat oxidation followed by autoclaving and simple cooking, whereas unprocessed (raw) hatchery waste showed maximum fat deterioration. PV, FFA and TBA decreased with all the levels of antioxidant addition when compared with samples without antioxidant fortification. At the end of storage period the significantly highest (P ≤ 0.05) levels of PV, FFA and TBA were observed in unprocessed samples without antioxidant addition, while the least degradation of fat was observed in extruded samples with 300 mg/ kg of antioxidant addition. In general, all the processing techniques as well as antioxidant addition checked the fat rancidity throughout the storage period as compared with raw samples without antioxidant addition, however synergistic effect of extrusion cooking and 300 mg/ kg of antioxidant addition was found to be most appropriate to keep the samples highly acceptable for 50 d of storage period.