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Influence Of Capsular And Ropy Exopolysaccharide-Producing Strepococcus Thermophilus On Mozzarella Cheese And Cheese Whey, B. L. Peterson, R. I. Dave, Donald J. Mcmahon, C. J. Oberg, Jeff Broadbent
Influence Of Capsular And Ropy Exopolysaccharide-Producing Strepococcus Thermophilus On Mozzarella Cheese And Cheese Whey, B. L. Peterson, R. I. Dave, Donald J. Mcmahon, C. J. Oberg, Jeff Broadbent
Nutrition, Dietetics, and Food Sciences Faculty Publications
We investigated the effect of capsular and ropy exopolysaccharide-producing Streptococcus thermophilus starter bacteria on Mozzarella cheese functionality and whey viscosity. Mozzarella cheeses were manufactured with Lactobacillus helveticus LH100 paired with one of four S. thermophilus strains: MR-1C, a bacterium that produces a capsular exopolysaccharide; MTC360, a strain that secretes a ropy exopolysaccharide; TAO61, a nonexopolysaccharide-producing commercial cheese starter; and DM10, a nonencapsulated, exopolysaccharide-negative mutant of strain MR-1C. As expected, cheese moisture levels were significantly higher in Mozzarella cheeses made with exopolysaccharide-positive versus exopolysaccharide-negative streptococci, and melt properties were better in the higher moisture cheeses. Whey viscosity measurements showed that unconcentrated …
Tryptophan Catabolism By Lactobacillus Casei Andlactobacillus Helveticus Cheese Flavor Adjuncts, S. Gummalla, Jeff Broadbent
Tryptophan Catabolism By Lactobacillus Casei Andlactobacillus Helveticus Cheese Flavor Adjuncts, S. Gummalla, Jeff Broadbent
Nutrition, Dietetics, and Food Sciences Faculty Publications
Microbial degradation of Trp is thought to promote the formation of aromatic compounds that impart putrid, fecal, or unclean flavors in cheese, but pathways for their production have not been established. This study investigated Trp catabolism by Lactobacillus casei and Lactobacillus helveticus cheese flavor adjuncts under carbohydrate starvation (pH 6.5, 30 or 37°C, no sugar) and near cheese-ripening (pH 5.2, 4% NaCl, 15°C, no sugar) conditions. Enzyme assays of cell-free extracts indicated that both species of Lactobacillus catabolized Trp to indole-3-lactic acid, and micellar electrokinetic capillary chromatography of culture supernatants showed this reaction occurred via successive transamination and dehydrogenation reactions. …