|
|
||||||||
Department of Nutrition and Food Sciences, Utah State University, Logan, UT 84322
ABSTRACT
Reduction of added phosphates in a bacteriophage inhibitory whey-based medium was possible through the application of pH control. Thirty-five active lactic strains and homologous bacteriophage filtrates were inoculated into whey media containing 0 to 2% added phosphates and continuously neutralized with 20% ammonium hydroxide. At 0% phosphates, all but five strains lysed; however, improved growth of these was evident in the media containing added phosphates. Twenty-one strains were protected by .5%, thirty by .75%, thirty-four by 1%, and all thirty-five by 2% added phosphates. All strains performed better in the whey-based medium than in a commercial bacteriophage inhibitory medium under pH control. Acid production was faster in bacteriophage-challenged cultures with reduced phosphate. Storage of a dehydrated bacteriophage inhibitory medium for 2 yr did not affect propagation characteristics of lactic culture. Examples of individual strain responses to the different phosphate percents are reported. Reduced phosphate enhanced milk clotting time, allowed faster culture development, provided protection against bacteriophage, and reduced phosphate content in finished products.
1 Contribution of the Utah Agricultural Experiment Station 2031. Approved by the director.
2 DPL Culture Service, 1750 Folsom Street, San Francisco, CA 94103.
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |