La diversité bactérienne et son évolution pendant la conservation de viandes bovines fraîches de différentes origines conditionnées sous vide

Poster (2012, December)

Le but de cette étude à été d'évaluer la diversité bactérienne et son évolution pendant la conservation de viandes bovine fraîches sous vide, en fonction de leur origine et du respect ou non d’une ... [more ▼]

Le but de cette étude à été d'évaluer la diversité bactérienne et son évolution pendant la conservation de viandes bovine fraîches sous vide, en fonction de leur origine et du respect ou non d’une température proche du point de congélation. Les dénombrements réalisés ont mis en évidence que les viandes d’origines britannique et belge testées présentent un écosystème microbien différent. Les analyses par approche métagénomique permettront d’éclaircir ces différences, surtout en ce qui concerne la présence de bactéries pouvant jouer un rôle "bioprotecteur" permettant d’améliorer la conservabilité des viandes. [less ▲]

Validation of a method for measuring the colour and determining the proportions of myoglobin redox forms on beef

Poster (2012, October 19)

The aim of this study was to validate the use of the spectrophotometer Minolta CM-600d for measuring the colour and the proportions of different myoglobin redox forms (oxymyoglobin, deoxymyoglobin, and ... [more ▼]

The aim of this study was to validate the use of the spectrophotometer Minolta CM-600d for measuring the colour and the proportions of different myoglobin redox forms (oxymyoglobin, deoxymyoglobin, and metmyoglobin) on the surface of meat. One vacuum-packaged (VP) striploin was supplied by a Belgian food wholesaler. It was cut in 3 cm thick steaks, repacked under vacuum and stored at −0.5 °C until analyses. The measurement of colour in the C.I.E. L*a*b* space and the determination of oxymyoglobin, deoxymyoglobin, and metmyoglobin were performed on VP and modified atmosphere-packed (70 % O2/30 % CO2 for 24 h) samples (n = 10). Results obtained were compared to two reference methods (colour measurement using a chromameter Minolta CR-400 and spectrophotometric determination of different myoglobin redox forms in aqueous meat extracts) by F-test for precision and t-test for accuracy. Statistic significance level was established at 5 %. The two colour measurement methods presented the same precision, when considering VP samples only, and different accuracies, probably because of the different detectors and observation angles used by both devices. The two methods for determining the different myoglobin forms presented also the same precision but different accuracies, probably due to the fact that oxygenation is favoured during some steps of the reference method (e.g. extraction, filtration). In conclusion, the results for colour measurement obtained by both devices cannot be compared. It is necessary to compare both methods for determining oxymyoglobin, deoxymyoglobin, and metmyoglobin in complete anaerobic conditions in order to eliminate the oxygenation bias. [less ▲]

Effect of duration and temperature of previous vacuum-packed storage on the oxidative stability of Belgian Blue meat packed in high-oxygen atmosphere

Poster (2012, August 13)

The aim of this experiment was to study the effect of duration and temperature of previous vacuum-packed (VP) storage on the oxidative stability of Belgian Blue meat packed in high-oxygen atmosphere. VP ... [more ▼]

The aim of this experiment was to study the effect of duration and temperature of previous vacuum-packed (VP) storage on the oxidative stability of Belgian Blue meat packed in high-oxygen atmosphere. VP striploins from bulls and cows were stored at −1 °C and +4 °C for up to 80 days and analyzed. These same meat samples were also repackaged under modified atmosphere (MA) – 70 % O2/30 % CO2 – at different times, stored 2 d at +4 °C and 5 d at +8 °C, and then analyzed. Meat from cows presented a lower loss of redness than meat from bulls. A low lipid oxidation was observed in VP samples, but an increase of lipid oxidation took place after MA repackaging. Meat from cows presented a higher -tocopherol content. A decrease of α-tocopherol content during storage was observed as well. The fat content was also higher in meat from cows than in meat from bulls. The duration and temperature of vacuum-packed storage influenced the sensitivity of Belgian Blue beef to pigment and lipid oxidation during subsequent high-oxygen storage. [less ▲]