Abstract
Most psychrotrophic bacteria have the ability to produce thermoresistant proteases that can destroy the quality of milk and dairy products. To investigate the population dynamics of psychrotrophic bacteria during refrigeration, three raw cows' milk samples (sample A comprising milk from 10 farms in Beijing, sample B comprising milk from 5 farms in Heihe, and sample C comprising milk from 7 farms in Harbin) were refrigerated at 0–5 °C and 5–10 °C. PCR-DGGE (Polymerase chain reaction-denaturing gradient gel electrophoresis) analysis revealed that the bacterial community profiles varied from geographical site to site, and with refrigeration temperature. The dominant psychrotrophic bacteria among the samples after storage were affiliated with the order Pseudomonadales. Following isolation and identification, 8 psychrotrophic isolates were selected as stronger protease producers and their growth and proteolytic activities were assessed. The results indicate that the composition of psychrotrophic bacteria play an important role in the determination of the quality of milk and dairy products.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.