Milk: quality of milk and dairy products - Content variation

8 important questions on Milk: quality of milk and dairy products - Content variation

By what 7 factors is fat and protein composition influenced?

  • Lactation state
  • animal health (mastitis = problem)
  • species (breeds and genetic variation)
  • farm management
    • feed
    • breeding
    • milking frequency
    • milking method and milk storage
  • fat content has high variation
  • protein variation is lower
  • seasonal variation
    • in NL -> year round production
    • in summer low fat content (eats more grass)
    • in winter high fat content (eats more concentrates)

How can a farmer reduce variation in milk contents?

  • Year round calving
  • combining milk from different herds
    • average is more constant
    • high hygienic standards

In what ways can bacteria levels in raw milk be kept low?

  • Good hygiene -> low contamination
  • cooling at 4 degrees
  • shorten storage time
  • Higher grades + faster learning
  • Never study anything twice
  • 100% sure, 100% understanding
Discover Study Smart

What happens with late-blowing in cheese?

Bacteria produce gas during ripening -> the gas damages internal structure -> cheese blows up -> off-flavour of the cheese

Quality of silage is important for late-blowing cheese prevention. What makes good silage good?

Good quality silage:
  • contains LAB (lactic acid bacteria) -> produces lactic acid in anaerobe conditions -> pH drops to 4,6 and prevents growth of other organisms

What happens in bad quality silage?

There are bad conditions for LABs: not enough sugar -> pH too high or too much O2 present -> spore forming bacteria can grow -> Clostridium tyrobutyricum is responsible for late-blowing

What does Cl. Tyrobutyricum produce and what happens to the milk?

Produces Butyric acid bacteria (BAB)
  • in bad silage 10^5 spores / ml
  • if cows eat it -> 10^6 spores / ml
  • 1 spore / ml can already cause late-blowing
  • spores of BAB survive pasteurisation and grow in dutch and swiss types of cheese

How can late blowing and BAB contamination be prevented?

  • Cleaning off teats can help (impossible to clean of all bacteria)
  • addition of nitrate prevents spores from growing
  • bactofugation
    • process done in the factory
    • centrifugation that removes large particles like spores
    • not all can be removed
  • best solution -> quality control of silage!

The question on the page originate from the summary of the following study material:

  • A unique study and practice tool
  • Never study anything twice again
  • Get the grades you hope for
  • 100% sure, 100% understanding
Remember faster, study better. Scientifically proven.
Trustpilot Logo