Time evolution of microbiological quality and content of volatile compounds in chicken fillets packed using various techniques and stored under different conditions

The aim of this study was to evaluate dependence of microbiological quality of chicken fillets and profile of volatile compounds in their packages on the applied packaging technique and storage conditions. Samples packaged in either normal atmosphere (AP, air packaging, PVC overwrap), in modified atmosphere with high oxygen content (Hi-O2-MAP), or in vacuum (VP) were stored in a cold room or exposed in a display case for 8 days. Quality of the meat was determined on day 1, 3, 6, 7, and 8 of the storage or exposition time. The microbiological quality of chicken fillets was assessed by determining the number of mesophilic aerobic bacteria, lactic acid bacteria, Pseudomonas spp. bacteria, and Enterobacteriaceae family bacteria. The profile of volatile compounds in the packaging of chicken fillets was also determined. At the beginning of the storage, bacteria of all major groups were growing at similar rates regardless of the used packaging technique. However, at the end of the period, the growth dynamic was diversified. The profile of the volatile compounds did not depend on the storage or exposition time regardless of the storage conditions and/or the packaging technique. The results of this study indicate that there is a potential to gain understanding of spoilage of packed chicken meat through the analysis of volatile compounds in association with microbiological analysis. However, future research should be based on standardized material with similar bacterial load.

The use of bioactive properties of sage preparations to improve the storage stability of low-pressure mechanically separated meat from chickens2

The aim of this study was to determine the effect of Salvia officinalis L. (sage) preparations on the storage stability of vacuum-packed low-pressure mechanically separated meat (MSM) from chickens stored at -18°C for 9 mo. Chilled low-pressure MSM coming from 4 production batches was obtained from the plant located in north-eastern Poland. All sage preparations-a water extract, ethanol extracts, and an essential oil-were prepared and added to the MSM under laboratory conditions. Five samples of low-pressure MSM were prepared that differed in terms of the type of sage preparation added: control-without addition of sage, WE-2.0% addition of water extract from sage, E40-2.0% addition of 40% (vol/vol) ethanol extract from sage, E70-2.0% addition of 70% (vol/vol) ethanol extract from sage, and EOS-0.1% addition of essential oil from sage. The MSM samples were assessed immediately after arrival into the laboratory and after 1, 2, 3, 4, 6, and 9 mo of storage. The quality changes of MSM samples were determined on the basis of the thiobarbituric acid reactive substances (TBARS) index and microbial analyses. On the basis of the TBARS index it was proved that addition of essential oil and (40% and 70% (vol/vol)) as well as water extracts of sage significantly (P < 0.05) slowed down fat oxidation processes in low-pressure MSM from chickens. The growth of mesophilic aerobic bacteria and psychrotrophic bacteria, coliforms, and Enterobacteriaceae was significantly (P < 0.05) restricted by all sage preparations tested. The most effective inhibitory effect for groups of bacteria analyzed in this study was demonstrated by sage essential oil, despite insignificant (P > 0.05) differences between the preparations. In conclusion, it was found that sage preparations are rich in bioactive compounds. Due to their antioxidant and antibacterial properties, especially sage oil and ethanol extracts may be recommended as an auxiliary factor to prolong the storage stability of frozen, vacuum-packed low-pressure MSM from chickens.