Skip to main content
padlock icon - secure page this page is secure

Phytosterol Effects on Milk and Yogurt Microflora

Buy Article:

$52.00 + tax (Refund Policy)


Phytosterols play a major role in functional foods. Their ability to reduce serum cholesterol in humans has been widely proven and they are now being added to various dairy based products. The present study investigated the potential antimicrobial activity of phytosterols in milk and their effect on yogurt starter cultures. A commercial phytosterol (0.26% to 1.8%, w/v) preparation (CPP) consisting of ß-sitosterol, campesterol, sitostanol, and campestanol had no effect on the standard plate count (SPC) and psychrotroph population in pasteurized milk stored at 4 °C. In addition, a challenge study employing Pseudomonas spp. in milk at 4 to 7 °C confirmed that the CPP was not antimicrobial. However, the addition of a dispersible CPP consisting of 0.72% phytosterol containing 0.02% to 0.03% sodium stearoyl lactylate (SSL) did appear to affect the SPC and psychrotrophic bacteria in refrigerated milk. The dispersible preparations did not, however, inhibit the growth of Pseudomonas. An investigation into the antimicrobial activity of SSL revealed that it alone had no effect on the SPC in milk. The CPP had no effect on growth and acid development by Lactobacillus bulgaricus and Streptococcus thermophilus during yogurt production at 33 °C and storage at 4 °C for 30 d. This is seen as a beneficial feature since growth and acid development by these organisms are crucial for yogurt quality. Saccaromyces cerevisiae and Aspergillus ochraceous added to yogurt as typical contaminants also were not inhibited. While the CCP was somewhat antimicrobial when formulated with dispersing agents, it otherwise had no antimicrobial activity.
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Keywords: antimicrobial; microbiology; milk; phytosterols; starter culture; yogurt

Document Type: Research Article

Publication date: April 1, 2008

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more