Production of Cultured Cottage Cheese Dressing by Bifidobacteria

¹ Dairy Section, Food Research and Development Centre, Agriculture and Agri-Food Canada, St. Hyacinthe, QC, Canada J2S BE3
² Centre de recherche en sciences et technolcgie du lait, Département de sciences et technologie des aliments, Pavillon Paul-Comtois, Université Laval, Ste-Foy, QC, Canada G1K 7P4

Fermentation conditions for the production of cultured cottage cheese dressing by bifidobacteria were determined by using freeze-dried concentrates of Bifidobacterium infantis. Cream dressing was fermented by addition of different amounts of inoculum of freeze-dried, milk-based media containing bifidobacteria. The use of milk-based media containing increasing percentages of UF retentate powder to replace lactose as a protective additive increased titratable acidity developed in cream dressing after 6 and 16 h of fermentation because of the increased buffering capacity. The supplementation of cream with a tryptic casein hydrolyzate did not reduce acidification times. The bacterial population of bifidobacteria was higher in cultured dressing that contained no salt than in that with added salt. In cultured dressing with added salt, the number of bifidobacteria decreased, pH declined, and titratable acidity increased. Finally, milk-based medium containing 12% ultrafiltered retentate powder at 3% inoculum can be used to acidify dressing (14% fat content) containing bifidobacteria at pH as low as 4.5 in <10 h. Cultured cottage cheese dressing with bifidobacteria may be a way of making ß-galactosidase available to lactose-deficient consumers. Moreover, the lactose content of dressing acidified to pH 4.5 decreased by 72%, the glucose and galactose content increased, and the lactase activity appeared to be uncoupled from growth and lactic acid production.

Key Words: bifidobacteria • sour cream • cultured cottage cheese dressing

Submitted on October 11, 1994
Accepted on February 15, 1995