Effect of length and temperature of storage on the ESR signal from various bones in irradiated chicken carcasses

Summary Eighty‐four whole, fresh chicken carcasses were randomly allocated to three groups of 28. Half of the carcasses within each group acted as controls (0kGy) and the remainder received an average irradiation dose of 5.27 kGy. The carcasses were then stored at either +20°C, +5°C or ‐20°C for periods of 1, 3, 7, 14, 21, 28, 56, 84 or 128 days. Bones from four sites within the carcass (tibia, femur, rib and sternum) were removed and prepared for analysis by electron spin resonance (ESR) spectroscopy. The strength of the ESR signal induced in the bones as a result of gamma irradiation was determined by double integration of these signals. The site from which the bone was removed had a highly significant effect on the ESR signal intensity and this response was highly correlated with bone crystallinity. Neither storage time, temperature nor the interaction of these two variables significantly affected the ESR signal strength in the bones from the four sites within the carcass. Nevertheless, there was a tendency for the signal to decrease with time when the samples were stored in dried from at +20°C.