Development of fermented dairy ingredients as flavor enhancers for bread

Optimal conditions for the preparation of concentrated fermented dairy ingredients for bread are presented. The inoculation of an equal mixture of milk and whey (20% dairy solids) with Lactobacillus casei subsp. rhamnosus gave good flavor development, without off-flavor, after 16 hr of fermentation, but best results were obtained after 24 hr. Incorporation of second patent wheat flour in the growth medium had a marked buffering effect and led to a higher total titratable acidity (TTA). Best results were obtained with whole wheat flour (30% w/v), which further increased TTA as well as flavor formation, especially at 38 o C. Partially replacing L. casei with L. helveticus and Streptococcus thermophilus (4% for each culture), followed by growth at 38 or 42 o C, gave higher TTA and higher levels of lactic acid and diacetyl (only at 42 o C). Compared to bread made without dairy solids, bread prepared with fermented dairy ingredients was mostly characterized by its higher content in lactic acid, ethanol, and diacetyl. Its aroma was described as pleasant (cheese-type) and more intense than that of the control. Fermented dairy ingredients can be dried and used as flavor enhancers (1-2%, db) in breadmaking processes with short fermentation periods or used as sourdough bases (up to ∼10%, db)