RESUMEN
This work aimed to study the role of gamma irradiation [1.5 and 3 kGy] in improving hygienic quality of fresh Bolti fish [Tilapia nilotica] stored at refrigerator temperature [3C] in prolonging the shelf-life extension and eliminating the pathogenic microorganisms. The results revealed that an irradiation dose of 3.0 kGy was most effective, not only for reducing the total contaminated bacteria, fungi and yeasts but also for a complete elimination of pathogenic Staph. aureus and E. coli; while Strep. faecalis showed some resistance during 30 days of storage without undesirable changes in their organoleptic properties compared with the control samples without any additives. Exposure doses of 1.5 and 3.0 kGy appeared to be most effective in reducing the viable counts of proteinase producing bacteria after 12 days of cold storage by 98.8% and 99.9% respectively, while a complete sterilization occurred at 3.0 kGy