2. Universidad Cardenal Herrera-CEU

The population dynamic of constitutive biota on 84 samples belonging to two different types of French fermented dry sausages during the ripening process in a pilot-scale ripening chamber was investigated. Samples were analyzed in three steps of their production: fresh product, first drying stage, and finished product. In addition, 180 strains of lactic acid bacteria were identified using a miniaturized biochemical procedure of characterization. In general, the number of lactic acid bacteria that evolved during the ripening process of French dry sausages increased during the first days of the process after which the number of these organisms remained constant at approximately 8 log CFU/g. Lactobacillus sakei and Pediococcus pentosaceus, bacteria added as starter, were the dominant species. Pediococcus urinaeequi, Pediococcus acidilactici, and particularly Lactobacillus curvatus were also present. Finally, we have to take into account that the controlled conditions of the pilot plant generally contribute to the homogenization of the behavior of the starter biota.

The sensitivity of different methods for the isolation and identification of Campylobacter, Listeria and Salmonella was compared, and their application in food safety control in a poultry slaughterhouse was evaluated. The VIDAS, SimPlate, Reveal and VIP systems were used, together with traditional microbiological methods. The study was carried out in a slaughterhouse and in the poultry carving room. One hundred and twenty samples (40 per microorganism) obtained from carcasses, viscera, different chicken parts, water and the environment were evaluated. For Campylobacter, the VIDAS system performed better than plate confirmation. The traditional method yielded results similar to those obtained with the SimPlate method. For Listeria, the plate count method proved less sensitive than the VIDAS, VIP and Reveal systems, which yielded similar results. For Salmonella, the VIDAS system displayed a detection rate comparable to that of traditional methods, while the Reveal system detected twice as many positive samples (16 in total). The Reveal method performed significantly better than either the plate count method or the VIDAS system. The alternative methods used here could be successfully applied in food safety control in poultry slaughterhouses, providing similar or better results and taking less time to perform. The VIDAS system, in general, and the Reveal system in the case of Listeria and Salmonella, appear to be effective alternatives to traditional methods.