Title: A comparative study of storage time of warm and cold water fish in view of the current market demands.
Abstract
Fillets from warm and cold water fish were purchased from respective processing plants and stored at 0°C and 5°C in commercial styrofoam boxes for as long as acceptable. During storage, sensory, microbiological and chemical tests were carried out. The warm water Nile perch Lates niloticus and the cold water Ocean perch Sebastes marinus stored at 0°C remained acceptable for 2-3 weeks and 1 week respectively. Fillets stored at 5°C reached the limit of acceptability within a week of the trials. The TPC at limit of acceptability was 106 -107 /g in plates incubated at 22°C and 104 in plates incubated at 37°C for both fish stored at both temperatures. The H2S- forming bacteria, were slightly more in fillets stored at 5°C than fillets stored at 0°C. Plates incubated at 37°C had fewer H2S- forming bacteria than plates incubated at 22°C. Correspondingly, the TVB-N was ≥ 20mg/100g and ≥ 25mg/100g for Nile perch and Ocean perch respectively. The TMA was five times more in Ocean perch (≥50mg/100g) than Nile perch (<10mg/100g) in both storage temperatures. The major bacterial spoilers in Nile perch were identified as belonging to Pseudomonas group 1 and 2.