Heat-induced whey protein gels: protein-protein interactions and functional properties.

Heat-induced gelation (80 degrees C for 30 min or 85 degrees C for 60 min) of whey protein concentrate (WPC) solutions was studied using small deformation dynamic rheology, small and large deformation compression, and polyacrylamide gel electrophoresis (PAGE). The WPC solutions (15% w/w, pH 6.9) were prepared by dispersing WPC powder in water (control), 1% (w/w) sodium dodecyl sulfate (SDS) solution, and N-ethylmaleimide (NEM) solution at a protein/NEM molar ratio of 1:1 or in 10 mM dithiothreitol (DTT) solution.

Serine metabolism in Lactobacillus plantarum.

This study investigated the metabolism of (L-) serine by Lactobacillus plantarum B3089 isolated from cheese. Serine was deaminated by growing cells to ammonia with the corresponding formation of acetate and formate. Serine was also deaminated by non-growing cells to ammonia but with the formation of acetate only (no production of formate).

Practical implications of lactate and pyruvate metabolism by lactic acid bacteria in food and beverage fermentations.

This article reviews the metabolism of pyruvate and lactate by lactic acid bacteria (LAB) involved in food and beverage fermentations with an emphasis on practical implications. First, the formation of pyruvate and lactate from a range of substrates, including carbohydrates, organic acids and amino acids, is briefly described. The catabolism of pyruvate and lactate by LAB is then reviewed.