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Fresh trout fillets and salmon slices packed in trays were obtained from two multinational chain supermarkets and evaluated for freshness and bacteriological quality immediately after packaging and during storage at 3 degrees C. Initial aerobic counts at 30 and 25 degrees C were significantly (P < 0.05) lower in trout fillets (5.27 +/- 0.57 and 4.87 +/- 0.80 log CFU/g, respectively) than in salmon slices, where levels in excess of 6 log CFU/g were found. In both products, initial Enterobacteriaceae counts were slightly higher than 3 log CFU/g and increased significantly during shelf life by approximately 3 log CFU/g. Most of the enterobacteria were identified as Citrobacter freundii, Hafnia alvei, and Enterobacter cloacae. On day 0, most probable number (MPN) counts of total and fecal coliforms were not significantly different, numbers of the latter group being approximately 4 MPN/g. Escherichia coli was only detected when fish was spoiled. Although initial presumptive Staphylococcus aureus counts were approximately 3 log CFU/g, only 4 of 84 selected colonies belonged to this species. Neither Salmonella nor antimicrobial residues were detected in any sample. Ethanol content in salmon slices did not significantly (P > 0.05) increase until they became inedible. Significant correlation (r = +0.72, P < 0.05) was observed between this chemical index and viable counts at 30 degrees C only when salmon slices were inedible. Trout fillets were acceptable for 7 days, and salmon slices showed signs of spoilage after 4 days. Although public health concerns associated with packed trout and salmon appear to be minimal, data on sensory quality, shelf life, and total viable and Enterobacteriaceae counts strongly suggest the need to improve the quality control systems used by European multinational retailers, especially for imported salmon.

A study about the influence of commercial packaging on physicochemical and microbiological characteristics of Spanish cured meat products was performed. For this purpose, 100 samples of fermented sausages (FS) and pieces of cured meat (P) were analyzed. Results for mean pH values were 5.12 (FS) and between 5.79-5.83 (P). All mean values for a w were under 0.90. Mean counts for mesophilic aerobic bacteria were more than 8 log cfu/g (FS) and they were between 4.47 and 7.61 log cfu/g (P). Microbiological groups of Enterobacteriaceae were not detected in more than twothirds of the samples. The presence of Staphylococcus aureus was frequent. Salmonella spp. and Listeria monocytogenes were detected, after enrichment, in 4 and 5 samples, respectively. Clostridium botulinum was not detected. A statistically significant (p < 0.05) absence of enterobacteria was observed in packaged samples. Características fisicoquímicas y microbiológicas de diversos productos cárnicos curados españoles RESUMEN Se ha llevado a cabo un estudio sobre la influencia que puedan tener las distintas presentaciones comerciales de productos cárnicos españoles sobre las características fisicoquímicas y microbiológicas de los mismos. Para conseguir este objetivo, 100 muestras de embutidos (FS) y piezas curadas (P) fueron analizadas. Los resultados para los valores medios de pH fueron 5,12 (FS) y entre 5,79-5,83 (P). Todos los valores de a w estuvieron por debajo de 0,90. Las medias de los recuentos para la flora aerobia mesófila fueron de más de 8 log ufc/g (FS) y entre 4,47-7,61 log ufc/g (P). Distintos componentes de la familia Enterobacteriaceae no fueron detectados en más de dos tercios de las muestras. La presencia de Staphylococcus aureus fue habitual. Salmonella spp. y Listeria monocytogenes fueron detectados, tras enriquecimiento, en 4 y 5 muestras, respectivamente. Clostridium botulinum no fue detectado. Fue observada una ausencia, estadísticamente significativa (p < 0,05), de enterobacterias en las muestras envasadas.

The objective of this research was to determine the behavior of Listeria monocytogenes in three types of sliced ready-to-eat meat products packaged under vacuum or modified atmosphere conditions and stored at three temperatures. Slices of about 25 g of chorizo (a fermented dry pork sausage), jamón (cured ham), and cecina (a salted, dried beef product) were inoculated with L. monocytogenes NCTC 11994. Slices were packaged in a vacuum or in a modified atmosphere (20% CO2, 80% N2). After packaging, samples were stored for 6 months at three temperatures: 3, 11, or 20°C. Microbiological analyses were performed after 0, 1, 7, 15, 30, 45, 90, and 180 days of storage. The type of meat product, the type of packaging, the temperature, and the day of storage all influenced microbial levels (P < 0.001). L. monocytogenes counts decreased throughout the course of storage in samples of chorizo (quick decrease) and jamón (gradual decrease). In cecina samples, counts of L. monocytogenes increased from day 0 to day 1 of storage and then remained constant until day 90 of the study. These results may be of use for enhancing the safety of these ready-to-eat meat product types. Additional evaluation of the behavior of L. monocytogenes in cecina is needed.