Effect of electron beam irradiation on the quality of vacuum-packed, chilled-stored tilapia fish chunks

Currently, there is an increasing demand for minimally processed or convenience food products without any quality loss. Electron Beam Irradiation (EBI) is a non-thermal processing technique used to preserve the nutrient value and shelf-life extension of food products. In the present study, the effect of electron beam irradiation on the quality of tilapia fish chunks was evaluated. Tilapia fish chunks were vacuum packed and exposed to 0, 2.0, and 4.0 kGy doses of electron beam irradiation and kept under chilled storage. Biochemical, microbiological, and sensory qualities were analysed for up to 41 days. pH (6.85 to 7.10), total volatile base nitrogen (TVB-N), peroxide value (PV) and thiobarbituric acid (TBA) content showed an increasing trend during storage. It was observed that TVB-N content was lower in the irradiated sample than control. Thiobarbituric acid reactive substances (TBARS) values were within the acceptable limits during storage. Microbiological analysis revealed that irradiated fish chunks had lower total plate count, Pseudomonas count and Brochothrix thermosphacta count compared to the control. The hydrogen sulfide formers count and Lactobacillus count were nil in the irradiated fish chunks. In terms of microbial and sensory qualities, it was found that electron beam irradiated samples had an extended shelf-life of 28-38 days (with respect to dose level), compared to the control which had a shelf-life of only 16 days. Keywords: Non-thermal processing, Peroxide value, Sensory qualities, Shelf-life, TBA, TBARS, TVB-N, Vacuum packing