Milk Flashcards
What authority monitors drug residues in milk?
Veterinary medicines directorate
What temperature should milk be stored at if it is collected daily?
6-8C
What temperature should milk be stored at if collected less than daily?
Less than 6C
What temperature must milk be transported at?
10C
How long can you store milk for unrefridgerated before collection?
2 hours
What organisms can still grow at fridge temperature?
Pseudomonas, listeria monocytogenes
What are the health risks of a milk from a cow with Staphylococcus aureus mastitis?
Enterotoxins lead to food poisoning
What are the health concerns with drinking milk from a cow with streptococcus agalactiae mastitis?
Bacteraemia and fatal meningitis in infants
What bacteria present biological hazards in milk?
Bacillus cereus E.coli Salmonella Campylobacter Staphylococcus Coxiella burnetti Leptospirosis
What is required cut offs for cows milk that will be heat treated before consumption?
SSC <400,000 cells
Total viable count <100,000
What controls are there on raw milk that goes directly for human consumption?
Raw milk - milk that has not been heated above 40c
Staphylococcus aureus microbiological criteria
What are the requirements of a raw milk producer?
Registered raw milk producing holding TB and brucellosis free Comply with hygiene rules Provide a health warning Inspected twice a year TVC performed quarterly
What is the temperature an time requirements for high temperature, short time pasteurisation? (Most common)
Greater than 72C for a minimum of 15s
- 25s recommended to kill Johne’s
What temperature is milk sterilised at?
110-130C for 30 minutes
What temperature is UHT milk made at?
135C for 1s plus appropriate holding time
What test is used to show the efficiency of pasteurisation?
Phosphatase test
What test indicates over heating during the pasteurisation process?
Peroxide test - lactoperoxidase is destroyed over 78C
What test indicates bacterial contamination in milk?
Resazurin test
Which test indicates milk spoilage?
pH and alcohol test
Which test detects antibiotics in milk?
Delvo test - inhibition of Bacillus stearothermophillus
What is the test called for listeria monocytogenes in milk?
Listeria monocytogenes
How is curd formation achieved?
The addition of either fermentative bacteria, renin or the addition of acid
Heated to 85C
What bacteria are added to yoghurt?
Lactobacillus and Streptococcus
Define cream
Milk fat content of at least 10%
