Combined effect of chitosan and modified atmosphere packaging for shelf life extension of chicken breast fillets

The combined effect of dipping in a chitosan solution (1 g/100 ml) and packaging under modified atmosphere (MAP, 70% CO₂, 30% N₂) on shelf life extension of refrigerated chicken fillets was investigated. Microbiological (Total Viable Counts, Pseudomonas spp., Lactic Acid Bacteria and Enterobacteriaceae), physicochemical (headspace gas composition, pH, color and Thiobarbituric Acid test) and sensory (odor and taste) parameters were monitored for up to 14 days. TVC were 3.9–4.9 log cfu/g lower on day 6 of storage in treated vs. untreated air-packaged samples with the strongest effect being shown by the combination of chitosan plus MAP. A similar reduction in LAB, Pseudomonads and Enterobacteriaceae was recorded during storage. pH values varied between 5.73 (day 8, for acetic acid treated samples) and 6.28 (day 6, for air-packaged samples). Malondialdehyde (MDA) values ranged between 0.19 and 0.80 mg/kg indicating negligible oxidation of lipids. The color parameter L* decreased with time in the air-packaged samples but remained unaffected in all other treatments. Parameters a* and b* were not significantly affected by the chitosan or the MAP treatments. Based on the microbiological and sensory data, shelf life of air-packaged, chitosan-treated, MAP-treated and chitosan/MAP treated samples was 5, 11, 12 and 14 days, respectively.