ABSTRACT
Shelf life extension of fresh ground meat stored at 4oC was investigated using either chitosan (1% w/w) or an oxygen absorber or the combination of the two. Aerobically packaged meat samples stored at 4oC were taken as controls. Parameters monitored over 10 day storage period were: microbiological (TVC, Pseudomonas spp., Lactic Acid Bacteria (LAB) and Enterobacteriaceae), physico-chemical (pH, TBA) and sensory (odor and taste) attributes. Microbial populations were reduced by 0.4-2.0 log cfu/g for a given sampling day, with the more pronounced effect being achieved by the combination of chitosan and the oxygen absorber. Of the two, the oxygen absorber proved more effective in reducing microbial populations. The TBA values for control samples, samples treated with chitosan and samples containing the oxygen absorber increased (0.88-2.9, 0.88-1.59 and 0.88-0.93 mg MDA/kg of meat respectively) during storage while for samples treated with both chitosan and the oxygen absorber TBA values decreased from 0.88 to 0.36 mg MDA/kg of meat. Changes in pH values for the different treatments were statistically insignificant (p > 0.05). Based on both sensory evaluation and microbiological analysis, shelf life of ground meat samples was: 3 days for control samples, 3-4 days for samples treated with 1% chitosan, 6 days for samples packaged with the oxygen absorber and 9 days for samples treated with 1% chitosan and packaged with the oxygen absorber.
