The effect of short-time microwave exposures on inoculated pathogens on chicken and the shelf-life of uninoculated chicken meat

Fresh skin-less chicken breasts were inoculated with Escherichia coli K12 and Campylobacter jejuni (5-6 log(10) cfu cm(-2)) and exposed to microwaves (2450 MHz) in an experimental microwave oven at full power (IEC 1138.8 W) for 10, 20 or 30 s. All three exposures had only a minimal effect on bacterial numbers, in some cases counts were higher after treatment, irrespective of treatment time. Exposure to microwaves for 20 and 30 s had some effect on meat appearance (signs of partial cooking were observed). Further trials were carried out using uninoculated skin-on breasts to determine if 30 s exposure had any effect on subsequent microbial growth and hence shelf-life. There was found to be no difference between the shelf-life of treated and untreated samples stored at 3 +/- 1 degrees C. Overall, the results indicate that short time exposure of microorganisms on chicken meat to microwaves has no significant effect on numbers or growth. (C) 2000 Elsevier Science Ltd. All rights reserved.