Use of a modified atmosphere masterpack for extending the shelf life of chicken cuts

Abstract

Portions (about 1 kg each) of chicken leg cuts packed in low density polyethylene bags were arranged in masterpack barrier bags injected with two different kinds of modified atmosphere: 80% CO2/20% N2 and 70% CO2/30% N2. All the samples packed in modified atmosphere, as well as the control samples packed in air, were dark stored at 3±1°C. The shelf life of the products was evaluated on the basis of microbiological and sensory criteria. The shelf life of the samples with initial mesophilic and psychotrophic bacteria counts of 5.38 and 5.72 log CFU/g, respectively, and stored under 80% CO2 was extended from 7 to 17 days, considerably longer than the shelf life increase achieved with the samples packed in a modified atmosphere containing 70% CO2, which increased from 10 to 14 days. The odour changes observed during refrigerated storage of all samples followed a uniform pattern, starting with an odour of ‘old chicken meat’ which gradually developed into rancid and, finally, putrid odours. The detection of putrid odours was the basic criterion for rejection of the products and correlated well with the microbiological evaluation data. At the end of the shelf life the appearance of the samples was evaluated as slightly to moderately different from their appearance at the start of the experiment. © 1998 John Wiley & Sons, Ltd.