: There is a current need for fresh‐cooked‐like yet shelf‐stable egg products for U.S. military combat rations. Novel thermal processes based on radio frequency (RF) energy can shorten the heating time and reduce overheating. This technology was explored to produce shelf‐stable egg products for combat ration development. Clostridium sporogenes (PA 3679) spores were used as a surrogate to validate the RF sterilization process to control Clostridium botulinum. Decimal reduction time (D value) of PA3679 in scrambled eggs was determined using aluminum thermal‐death‐time (TDT) tubes. The thermal inactivation kinetic information was then used in inoculated pack studies to validate a novel thermal process based on 27.12 MHz radio frequency (RF) pilot scale unit. Trays of scrambled eggs inoculated with PA 3679 were subjected to 3 processing levels: target process (F0 about 5.3 min), under‐target process (F0 about 3.0 min), and over‐target process (F0 about 9.1 min). The results of the microbial challenge study showed that microbial destruction from the RF process agreed with sterilization values calculated from time‐temperature data measured at the cold spot in the treated trays. A comparison of RF‐ and retort‐treated scrambled eggs showed significant differences in the degree of lightness (L*) and redness (a*). RF‐processed egg was less brown compared with conventional retorted eggs. Retort treatment of fully cooked scrambled eggs had higher hardness, springiness, and smaller cohesiveness than RF ‐treated samples. This study suggests that RF thermal processes can produce safe, shelf‐stable sterilized scrambled eggs for both military and civilian uses.
Thermal resistance of Clostridium sporogenes (PA 3679) was determined at 115.6°C, 118.3°C, and 121.1°C (240°F, 245°F, and 250°F, respectively) in phosphate buffer (pH 7.0) and mashed potatoes (pH 6.3) using aluminum thermal-death-time (TDT) tubes developed at Washington State Univ. D-values were 1.8, 1.1, and 0.62 min in phosphate buffer and 2.2, 1.1, and 0.61 min in mashed potatoes at 115.6°C, 118.3°C, and 121.1°C, respectively. Z-values were 12°C and 10°C in phosphate buffer and mashed potatoes, respectively. The thermal inactivation kinetic results were then used to validate a novel thermal process based on 27.12 MHz radio frequency (RF) energy. Trays of mashed potatoes inoculated with PA 3679 were subjected to 3 processing levels: target process (F 0~4 .3), under-target process (F 0~2 .4), and over-target process (F 0~7 . 3). The microbial challenge test data showed that microbial destruction from the RF process agreed with the calculated sterilization values. This study suggests that thermal processes based on RF energy can produce safe and shelf-stable packaged foods.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.