Effect of microwave and open flame heating on the microbial counts and weight loss of eel.

Abstract

The decimal reduction time and the thermal death time of E. coli Type I in eel bouillion were studied. And the effects of microwave and open flame heating on microbial inactivation and weight loss of eel fillet were compared. The thermal death time regression curve of E. coli in eel bouillion was found to have a Z value =5.1°C. The values read from this curve were accurate over 90% confidence. The lethal effect of microorganisms in eel fillets treated by open flame was higher than that of microwaves at 2450 MHZ if the results were evaluated under equal weight losses. The weight loss of flame-heated fillet was 0.43% for every degree (°C) increase in temperature within the range from 50°C to 80°C. And for microwave-heated fillet was 0.44% between 42°C and 87°C. The combination of heating for 2 min over flame and followed by 15 seconds in microwaves had almost the same effect in weight loss and microbial counts as that heated for 5 min by flame alone.