Abstract

• This research focuses on the food preservation by irradiating of fermented prawn. The prawns were collected from Thanlyin market and fermented as home-made. This sample was irradiated with 3 kGy dose of Co-60 gamma source for 2:22:18 and stored in a dry place under room temperature. Non-irradiated fermented prawn sample was used for comparative study. Induced radioactivity of irradiated fermented prawn was monitored by using NaI (Tl) Scintillation Gamma Counter. Some nutritional values of non-irradiated and y-irradiated samples such as water (65.34 % and 65.09 %), ash (0.08 % and 0.11 %), protein (16.00 % and 17.30 %) and fat (0.43 %and 0.52 %) were determined by analytical methods. There were no significant changes in nutritional values of y-irradiated sample compared with non-irradiated sample. The shelf life of non-irradiated and y-irradiated fermented prawns were studied by using microscope for seeking spoilage and pathogenic bacteria at room temperature. Shelf life of y-irradiated sample was found to be prolonged nearly two times than that of non- irradiated sample. From the monitoring of induced activity, there were no considerable activities above background. Thus radiation can be used for the shelf life extension of fermented prawn and is not harmful to health. From the observation of gamma radiation effect on microorganism and morphological tests were used to evaluate the unknown bacteria in y-irradiated sample. From these investigations, the populations of Cocci and Bacilli bacteria groups in y-irradiated sample were significantly decreased than that of non-irradiated sample.