USE OF HIGH HYDROSTATIC-PRESSURE AND IRRADIATION TO ELIMINATE CLOSTRIDIUM-SPOROGENES SPORES IN CHICKEN BREAST

High pressure has been studied for its usefulness in reducing microbia l contaminants in foods. We sought to determine whether this technolog y could be used in combination with irradiation to develop shelf-stabl e products. We first determined the optimal pressure, temperature, and time conditions that would result in maximum reduction of Clostridium sporogenes spores in fresh chicken. At ambient temperature, a pressur e of 6,800 atm for up to 60 min resulted in a 5-log-unit reduction. He ating the samples during pressurization at 80 degrees C for 20 min res ulted in the lowest number of survivors compared to samples that were heated and pressurized for only 1 and 10 min. Further, irradiation at a medium dose (3.0 kGy) before and after pressurization at 6,800 atm a nd 80 degrees C for 1, 10, and 20 min revealed no significant differen ces in spore counts between samples that were pressurized and then irr adiated or vice-versa. We then examined the effect of high pressure in lowering the irradiation dose necessary to eliminate all spores. The irradiation D value of C. sporogenes spores was calculated to be 4.1 k Gy. Samples were then irradiated at various doses followed by pressuri zation at 6,800 atm at 80 degrees C for 20 min. The irradiation D valu e was lowered to approximately 2 kGy, indicating that a combination of high hydrostatic pressure and irradiation can be used to produce chic ken with an extended shelf life without the use of high irradiation do ses.