Effect of vacuum-packaging storage on the quality level of ripened sausages.

To investigate the influence of vacuum-packaging on both the sensory properties and the degradation level of their lipid fraction, some ripened sausages (30 days) were further stored for 40 days under vacuum-packaging and compared to sausages kept unpackaged for the same period of time. The same kind of sausages was used in both the trials. As for the sensory properties, after storage the unpackaged sausages showed significantly higher mean scores of red intensity and global flavour than vacuum-packed ones (p<0.01 and p<0.05, respectively) indicating a brighter red colour of meat and a greater overall appreciation by the panelists. Regarding the degradation of the lipid fraction, significantly higher values (p<0.01) of the free fatty acids were detected in the vacuum-packed samples, indicating a greater hydrolytic degradation of their lipid fraction as compared to the sausages stored unpackaged. The oxidative degradation of the fatty fraction, measured by the combined use of conventional (determination of peroxide value and TBA test) and non-conventional techniques (HPSEC analysis of the polar compounds of the lipid fraction) showed significant increases during storage for both the storage conditions considered but no significant differences were found between packaged and unpackaged sausages.