Ozone action on survival and storage life of live and chilled tilapia

Abstract

The effects of applying ozone treatment to live pond-raised tilapia on the survival of live fish and length of storage of chilled fish were evaluated according to sensory, chemical, physical, and bacteriological tests. Long-term low-level ozonation extended survival and improved the physi- cal state of live fish in a tank and may be feasible for use in fish markets to improve commercial quality of live fish. Ozone treatment of tilapia while still alive prolonged their storage life as chilled tilapia by 12 days (40%) and improved their quality when stored at 0°C but had little effect at 5°C. The improvement probably resulted from an initial reduction and prevention of growth of spoilage bacteria such as Pseudomonas fluorescens, Shewanella putrefaciens, and Aeromonas sobria. At 0°C, P. fluorescens was most sensitive to ozone, while Brevundimonas diminuta and Pseudomonas putida were not. The combination of ozone pretreatment and storage at 0°C appears to be a feasible means of prolonging the storage life of chilled tilapia.