THE SELECTION OF BIFIDOBACTERIA FOR THE MANUFACTURE OF FERMENTED MILKS

Three Bifidobacterium bifidum strains, isolated from the stools of infants fed breast milk exclusively, and four standard strains of the same organism, three from the National Collection of Dairy Organisms, Reading, UK and one from the National Collection of Dairy Organisms, NDRI, Karnal, India, were examined for their suitability in the manufacture of fermented milks. Suitability was assessed on the basis of the technological criteria of titratable and volatile acid production, diacetyl and acetoin production and proteolytic activity, and the dietetic criteria of lactic acid production, microbial growth and antibiotic activity against Shigella dysenteriae. On the basis of dietetic criteria, two of the UK standard strains, NCDO 1452 and NCDO 1454, and the Indian strain, NDRI, were found to be the most suitable. When both dietetic and technological criteria were considered, strain NDRI was the best for the manufacture of B. bifidum-based fermented milks.