Effect of potassium sorbate dip-treatment in vacuum packaged Lethrinus lentjan fillets under refrigerated storage

The effect of vaccum packaging on the shelf life of refrigerated Lethrinus lentjan fillets was investigated. The fillets were dip-treated with various concentrations (1.0%, 1.5% and 2.0%) of potassium sorbate, vacuum-packaged and stored in refrigeration temperature (4°C ± 1°C). The control and treated fillets were analysed periodically for biochemical (pH, TMA-N and TVB-N and FFA) and microbiological (TPC, psychrophiles, total anaerobes/facultative anaerobes, Lactobacillus and Staphylococcus counts), sensory (skin appearance, discoloration, gaping, texture and odour), quality characteristics. The shelf life periods of control packs were about 7-8 days, whereas the potassium sorbate treated fillets had an extended storage life of 20 days. Vacuum packaging alone could not prolong the shelf life of fillets in refrigeration temperature. Vacuum packaging in combination with potassium sorbate dip-treatment was found to delay the spoilage to a considerable extent by slowing down the microbial growth.