Evaluation and predictive modelling of the effect of chitosan and gamma irradiation on shelf life of chilled chicken meat

In present study, the antimicrobial effect of chitosan, gamma irradiation and their usefulness in improving the shelf life of chilled chicken samples was evaluated. The data obtained from the microbial and chemical analysis of 127 samples was fitted using Gompertz and Parabola function of Origin Pro8 software. The maximum specific growth rate (μ_max) and the lag phase (•) duration of total viable load of microbes in untreated sample was 0.91 (log cfu/g)/day and 3.91 days, respectively. The μ_max of samples treated with irradiation, chitosan and their combination was estimated to be 0.42, 0.33, 0.31 (log cfu/g)/day; while the lag phase was estimated to be 4.78, 2.81, 5.04 days, respectively. Statistically significant difference in TBARS and total soluble protein content among different treatment groups was observed after 11 days. Mathematical model was developed and validated with confidence level of 95%. This model was found to be fit for predicting the shelf life of treated chicken meat if initial count is known. The model also enables variable labelling of 'best before date' of the chicken mince, thus ensuring the microbial safety and sensory qualities of chicken meat, which depends largely on the initial conditions of meat. (author)