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Flashcards in Dairy and Milk Science Deck (38):
1

What is pasteurization

invented by Louis Pasteur. a process which uses heat to destroy all pathogenic bacteria from milk and other juices.

2

Does pasteurization kill all bacteria?

no, many non-pathogenic bacteria remain

3

What is one of the most heat resistant pathogenic bacteria in milk? and what temperature is it destroyed at

Q fever bacteria (coxiella burneti) destroyed at 145F at 30 minutes

4

What does milk loose it's flavor and consistency if cooked too hot?

because the albumin coagulates which changes the sugars, fats and salts in the milk.

5

What are the 5 pasteurization methods

the VAT (Batch) Method
HTST High Temp Short Time Method
High Heat Short Time Method
Ultra High Temperature Method
Instantaneous Method

6

What is the VAT (Batch) Method

145 for 30 minutes typically used for cultured dairy products such as sour cream and yogurt

7

What is the HTST Method (name the three common temperatures and times)

Milk goes through a continuous flow process where it is carefully heated.

161 for 15 seconds
166 for 15 seconds (if Q fever in product)
175 for 25 seconds for high fat products such as ice cream

8

What is the high heat short time method of pasteurization

similar to ultra high temp.

between 191 and 212 for a second or less

9

What is the ultra high temperature method

in a vacuum chamber 194 for 3/4 second

used for high sugar/fat products such as half and half and whipping cream

10

What is one of the benefits of ultra high temp pasteurization

gives a product a very long storage life. some products can even be stored at room temperature

11

What is the instantaneous method of pasteurization

280 for a fraction of a second. not really used because it's hard to maintain consistent temperature. it is used for some shelf stable dairy creamers

12

Which method has been found to product the best results

high temperature short time

13

What are some of the downfalls of the VAT method

bubbles in the vat can cool the milk resulting in improper pasteurization

to counter act something hot air is blown over the vat

14

What are some downfalls to the HTST method

milk must be preheated first

15

What happens if the milk does not get hot enough as it passes through the coils in the HTST method

it is automatically recirculated back through

16

What are the names of the 5 standards for bacteria in milk

grade A raw milk
grade A pasteurized milk
grade b raw
grade b pasteurized
certified raw milk

17

grade A raw milk

less than 50,000 bacti per ml

18

grade A pasteurized

less than 15,000 bacti per ml (standard plate count)

19

grade b raw

less than 1,000,000 bacti per ml

20

grade b pasteurized

less than 50,000 bacti per ml
typically used for industrial processes (where it will be heated further)
not direct to consumer

21

certified raw milk

same stds as grade a
less than 15,000 bacti per ml

22

how much vitamin D is added to most milk products

400 ius

23

What two vitamins does pasteurization destroy in milk

vitamin D and C

24

What is homogenized milk

milk that has been centrifuged so the fat globules break up into a non settling liquid

25

Name 10 diseases that may be found in milk

brucellosis
bovine tuberculosis
staphylococcus
typhoid
salmonella
streptococcus
septic sore throats
hep a
q fever
scarlet fever

26

how long before the birth and after the birth must milk from a calving cow be disposed of

15 days prior and 5 days after

27

How often are most cows examined

every 6 years

28

milking cows are testing every year for what?

tuberculosis

29

Can milk pails be used?

NO, milk is now collected and stored in bulk storage tanks

30

The average milking cow produces __ to __ gallons of milk per day

5 to 7

31

What is bovine mastitis

aka scarlet fever

a streptoccus infection of the cows udder

32

What would a leucocyle count tell you about a cows health?

it's a white blood cell count, it will tell you if they have an infection

33

What are 4 foreign substances that can be found in milk?

antibiotics
insecticides
radioactivity
milkstone

34

what are two radioactive materials that have been found in milk?

radioactive strontium and iodine isotopes

35

What are milkstones

build up of calcium and magnesium from milking equipment that can get into milk

36

What is the phosphatase test used for?

to test for the phosphatase enzyme which if present in milk indicates improper pasteurization

37

What is the ring test (blue ring test)

tests for brucellosis in cows. a blue ring will form in the test bottle

38

The methylene blue test is aka as ________ and tests what about milk?

the milk reduction test

tests overall quality of milk, mainly checking to see fi there is a large number of bacteria in the milk sample