Chemical analysis carried out on dairy milk products are of considerable importance in the quality control of finished products, for example to determine the freshness period of a product, or its expiration date.

Food safety is essential in milk and dairy products industry. The healthy image that these products have, particularly the perception of its safety and quality, is always under close scrutiny due to some outbreaks of human illnesses and product recalls implicating milk, cheese, ice creams, etc. Therefore, a thorough analysis with the indicated culture media is essential to ensure safety for consumption.

Culture media for Dairy Products Industry

For the identification of all these pathogens of importance in the safety of dairy products industry, there are several specific culture media:

  • Bile Esculin Agar: isolation and identification of Group D Streptococci.
    Foods of animal or vegetable origin obtained by fermentation may have a very high content of group D streptococci, which are present as natural flora. These Streptococci can be used as indicators of highly resistant enteric pathogens. They are also useful in the analysis of thermally processed foods and in determining the effectiveness of disinfection and cleaning systems.

  • Bryant-Burkey Broth Base: detection of lactate fermenting clostridial species, in milk and dairy products, particularly Clostridium tyrobutyricum.
    This bacterium is responsible for the "late spoilage" in certain types of cheese and it gives them an unpleasant taste and odor, which comes to crack and even pop cheese.
  • Chloramphenicol Agar: selective medium for isolation and enumeration of molds in milk and dairy products. Recommended by ISO.

  • Desoxycholate Agar: isolation and enumeration of Coliforms in dairy products

  • Enterobacter sakazakii Isolation Chromogenic Agar:isolation of presumptive Enterobacter sakazakii in milk products.
    Powdered milk formulas are the foods most commonly implicated in the growing of this organism, so this bacterium affects babies specially.

  • Esty Broth and Esty Medium: selective media for cultivation of Streptococcus thermophilus in yogurt.
    Presence of this microorganism is the main difference between traditional yogurts and the yogurts "pasterized after fermentation" (that don't need cold temperature), which don't contain it.

  • Glucose Choramphenicol Agar and Glucose Choramphenicol Broth: selective media for isolation and identification of yeasts and molds in dairy products.

  • KAA Confirmatory Agar and KAA Presumptive Broth:isolation and confirmation of Lancefield Group D Streptococci in foods. (see Bile Esculin Agar).

  • Lauryl Sulfate Truptose Broth modified:Selective enrichment medium for Enterobacter sakazakii (see Enterobacter sakazakii Isolation Chromogenic Agar).

  • M17 Agar: cultivation and enumeration of lactic Streptococci in milk and dairy products. Recommended for isolation of Streptococcus thermophilus in yogurts. Also for cultivation and maintenance of cheese and yogurt fermentations.

  • Rothe Broth: for the quantitative determination of fecal Streptococci.

  • Standard Methods Agar with Powdered Milk: for bacterial plate counts of microorganisms from milk and dairy derivatives (APHA* Formula).