HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ventling, B. L. Articles by Mistry, V. V. Search for Related Content PubMed PubMed Citation Articles by Ventling, B. L. Articles by Mistry, V. V.

Growth Characteristics of Bifidobacteria in Ultrafiltered Milk

Minnesota-South Dakota Dairy Foods Research Center, Dairy Science Department, South Dakota State University, Brookings 57007-0647

Five replicates of raw skim milk were ultrafiltered at 54°C to total protein concentration ratios of 2:1, 3:1, 4:1, and 5:1. Bifidobacterium bifidum and Bifidobacterium longum were inoculated at 5% into skim milk that was not ultrafiltered (1:1) and into ultrafiltered skim milks followed by incubation at 37°C. The mean maximum bacterial count (colony-forming units per milliliter) range and protein concentration ratio were from 6.25 x 10⁸ to 1.69 x 10⁹, skim milk; 4.42 x 10⁸ to 3.56 x 10⁹, 2:1; 2.62 x 10⁸ to 3.94 x 10⁹, 3:1; 6.67 x 10⁸ to 1.88 x 10⁹, 4:1; and 2.90 x 10⁹ to 3.59 x 10⁹, 5:1. The mean developed acidity at maximum B. bifidum population in skim milk was .16%, and pH was 5.55. The 5:1 concentrate had a higher mean developed acidity of .57% at pH 5.35, which was similar to that of the skim milk. Trends were similar for B. longum. Because of the increased buffering capacity of highly concentrated ultrafiltered milks, pH 5.5 or higher was maintained longer, along with high developed acidity. Scanning electron micrographs showed distinct morphological variations between bifidobacteria grown in broth versus those grown in the milks.