RESUMEN
Microbiological developments during industrial meat fermentations (salami), made with and without commercial starter cultures, were followed at two factories in Germany and Italy. In the German product microbial growth was evident only for the first 48 h, followed by a gradual decline in numbers of most micro-organisms. The pH fell from 5.8 to 4.8 in the 28 d required for production. In Italy a similar situation was seen, except that a second period of bacterial growth began around 15 d, coincident with the appearance of intentional surface mould growth which reversed the pH fall, the final pH being 6.2. The German starter culture was a mixture of Lactobacillus plantarum and Staphylococcus carnosus, whereas in Italy only Staph. carnosus was used. The strain of Lact. plantarum used did not grow in the German product whereas the Staph. carnosus grew well in both products to form a substantial proportion of the final microflora.
Asunto(s)
Fermentación , Microbiología de Alimentos , Lactobacillus/crecimiento & desarrollo , Productos de la Carne/microbiología , Staphylococcus/crecimiento & desarrollo , Bacteriófagos/aislamiento & purificación , Alemania , Concentración de Iones de Hidrógeno , ItaliaRESUMEN
Low-resolution nuclear magnetic resonance and enzymatic glycerol estimation were compared with a solvent extraction method for estimating the intracellular lipid content of lipid-accumulating yeasts. Both methods correlated well with the solvent extraction procedure and were more convenient with large numbers of samples.