Effects of gamma irradiation and chitosan edible coating on the bacterial, chemical and sensory properties of chicken meat

Irradiation as a method of meat and poultry preservation has excellent potential to improve meat safety and extend the shelf life. The main concern of irradiating meat، however، is the organoleptic quality changes that occur. The present study was conducted to evaluate the combined effect of low-dose gamma irradiation (2/5 kGy) and chitosan edible coating (2%) on the shelf life of chicken breast meat. Samples were separated into four groups; uncoated and unirradiated control (C)، coated with chitosan (CH)، irradiated and uncoated (I) and coated with chitosan and irradiated (ICH). Samples were stored at 0-4°C and evaluated periodically for microbiological (aerobic mesophilic and psychrotrophic counts)، chemical (TBA، pH، aw) and sensory (odor، appearance and overall acceptability) characteristics. Microbial analysis indicated that gamma irradiation and coating had significant effects (P<0. 05) in reducing the mesophilic and psychrotrophic counts with at least a 14-day extension of shelf life. The chitosan-coated products showed lower TBA and pH values than the uncoated samples for up to 21day of storage at 0-4°C. No significant (P>0. 05) differences in TBA values of samples were observed due to irradiation. The results indicated that the application of chitosan coating significantly improved (P<0. 05) sensory quality of samples. None of the sensorial characteristics (odor، appearance، overall acceptability) was significantly affected by gamma irradiation (P>0. 05). This study thus clearly indicated that the effect of chitosan coating plus irradiation on samples was to retain their good quality characteristics and extend the shelf life during refrigerated storage، which was supported by the results of microbiological، chemical، and sensory evaluation analyses.