Inulin was used as a prebiotic to improve quality of skim milk fermented by pure cultures of Lactobacillus
acidophilus, Lactobacillus rhamnosus, Lactobacillus bulgaricus and Bifidobacterium lactis, binary co-cultures
with Streptococcus thermophilus, or a cocktail containing all them.
Inulin supplementation to pure cultures lowered the generation time, with particular concern to S. thermophilus and L. acidophilus.
The generation time of all micro-organisms decreased in the following order: mono-cultures, co-cultures,
cocktail.
It was demonstrated a synergism between S. thermophilus and the other strains and a bifidogenic
effect of inulin.
Enumerations of L. rhamnosus in cocktail markedly decreased compared to cocultures
likely because of greater competition for the same substrates.
The results of this work highlight the industrial potential of the cocktail, mainly in terms of fermentation acceleration.