Extending the shelf life of fish balls using gamma irradiation

Hany A. Shawki1; Amira E. A. El-Hanafy2

and Esam M. Sallam1

1 Nuclear Research Center, Atomic Energy Authority, Egypt.

2 Central Lab. for Aquaculture Research, Agriculture Research Center, Egypt.

Received 13/ 11/ 2012 Accepted 23/ 12/ 2012

Abstract

The present study was conducted to evaluate the effect of low dose gamma irradiation (0, 1, 2, 3 and 5 kGy) and some spices on chemical, microbiological and sensory properties of silver carp fish balls during cold storage at 4 ºC ±1 for 36 day. Chemical composition (moisture; protein; fat, ash and carbohydrate) of fish balls was determined at the beginning of cold storage period. At periodic intervals, quality of silver carp fish balls was determined by sensory evaluation (appearance, odour and texture); freshness index (total volatile bases nitrogen (TVBN); Trimethylamine (TMA); Thiobarbituric acid (TBA) and pH. Microbiological parameters, Total bacterial count (TBC); psychrophilic bacteria; Enterobacteriaceae and mould & yeast counts were carried out. The results indicated that, fish ball samples without irradiation were rejected after 18 day, in comparison with 9 days for raw silver carp minced fish at cold storage whereas the shelf life of irradiated fish balls were 24; 30 ; 33 and 36 days for the fish balls irradiated at 1, 2, 3, and 5 kGy, respectively.

It could be concluded that shelf life of fish balls produced from silver carp fish could be extended by using gamma irradiation in combination with refrigerated storage especially at 3 kGy that can keeping the quality product with prolonged shelf life