ELECTROPHORETIC ANALYSIS OF PROTEINS FROM CHICKEN AFTER IRRADIATION AND DURING COLD-STORAGE

The SDS/polyacrylamide gel electrophoresis method was tested to determine whether it was suitable for the detection of the pre-irradiation of chicken. The electrophoretic pattern of unirradiated Pectoralis major muscle contained 26 proteins in the range 372 391 to 15 026 daltons. The radiosensitivities of various proteins in the untreated samples were investigated. Irradition with 6 kGy caused the complete disappearance of five proteins but induced the appearance of six new proteins as well as considerably altering the molecular weights (MW) of many proteins. Samples irradiated with 10 and 20 kGy were also distinguishable from either unirradiated or the 6-kGy irradiated samples. At least 19 and 25 new protein fractions were induced upon irradiation with 10 and 20 kGy, respectively. Changes in unirradiated and irradiated muscle proteins were followed during cold storage at 4 ± 1°C. Slower rates of protein breakdown characterized the higher irradiation doses. At the end of shelf-life of different samples, i.e. 12 (0 kGy), 32 (6 kGy), 55 (10 kGy) and 75 (20 kGy) days, the numbers of protein bands were dramatically increased to 48, 46, 48 and 61, respectively. All of these bands were characterized by a partially reduced MW. © 1990.