DEVELOPMENT OF FISH SAUSAGE FROM MULLET Mugil cephalus AND IT’S QUALITY EVALUATION DURING REFRIGERATED STORAGE

Fish protein hydrolysate (FPH) was prepard from Tilapia fish wastes using optimised conditions of 50°C, pH 6.5 ± 0.2 and hydrolysis time of 1 h. Papain E / S using papain enzyme.  The prepared FPH was incorporated at 0, 5, 10 and 20% levels in the sausages that were prepared from Mugil cephalus. The prepared fish sausage was stored in refrigerated condition at 2ºC ± 1ºC for 20 days. During the storage, initial proximate composition biochemical, microbial and organoleptic changes in fish sausage were analysed. The analysis of Bio-chemical quality indices include, Total Volatile Base-Nitrogen (TVB-N), Thiobarbituric Acid (TBA), Trimethylamine (TMA), Free Fatty Acids (FFA), Peroxide Value (PV) and pH value. Total Plate Count (TPC) was estimated to study the microbial quality. The sampling was carried out on FPH treated and untreated raw fish sausage periodically for every 4 days during refrigerated storage period and sensory analysis performed after frying raw sausage periodically for every 4 days.

A decrease in PV, TBA, TVBN, FFA and TPC was observed with the increase in the concentration of FPH. The PV values of sausages incorporated with 0, 5, 10 and 20% of FPH were 14.33, 11.26, 10.49 and 10.11 mg of hydro peroxide/kg of fat respectively at refrigerated temperature storage for 20 days. The TBA values of sausages incorporated with 0, 5, 10 and 20% of FPH were 3.34, 2.06, 1.61 and 1.19 mg of malonaldehyde/kg of fat respectively during refrigerated storage for 20 days. The FFA values of sausages incorporated with 0, 5, 10 and 20% of FPH were 7.49, 2.47, 2.25 and 2.08 % as Oleic acid respectively at refrigerated storage for 20 days. The TVB-N values of control sample were 18.67 mg/100 g and the FPH treated samples were 16.33, 15.16 and 14.31 mg N/100 g at refrigerated storage for 20 days. The TPC of the control sample is 6.84 log cfu/g and the FPH treated samples at 5%, FPH 10% and FPH 20% have the TPC values of 4.74, 4.06 and 3.35 log cfu/g respectively on 20^th day of refrigerated storage. The control sample was deteriorated at the 12^th day and the samples with FPH were acceptable till the end of storage and the acceptance was in the order, FPH 10% > FPH 5% > FPH 20% (Table 1). So it is concluded that the incorporation of FPH prepared from Tilapia waste can enhance the shelf life of the product at 10% incorporation of FPH.