Milk quality

Question 1

List the milk producers of the world.
Which is the top producer?

Answer 1

India

Question 2

What is the functional unit of the mammary gland ?

Answer 2

The alveolus of mammary gland (udder) is the
functional unit for milk production

Question 3

Mammary gland is made up of two layers of cells
1. __________ are the milk producing cells
 also called mammary ________ cells
 They are located on the ________ inside mammary gland
2. _________ _________ cells
 They are like ________ muscle
 They are located surrounding _________

Answer 3

Mammary gland is made up of two layers of cells
1. lactocytes are the milk producing cells
 also called mammary epithelial cells
 They are located on the surface inside mammary gland
2. basal myoepithelium cells
 They are like smooth muscle
 They are located surrounding lactocytes

Question 4

_________ L of blood comes to the mammary gland to produce 1 L of milk.

Answer 4

90,000

Question 5

During lactation, or milking, when we touch the teat the animal feels that sense. __________ is released from pituitary gland –> _______ muscle of mammary gland –> squeezes ________ cells, each containing milk, which is then released.

Answer 5

During lactation, or milking, when we touch the teat the animal feels that sense. Oxytocin is released from pituitary gland –> smooth muscle of mammary gland –> squeezes epithelial cells, each containing milk, which is then released.

Question 6

80% if milk is stored in ________, only 20% is stored just above the _____

Answer 6

80% if milk is stored in alveoli, only 20% is stored just above the teat

Question 7

A cow has how many quarters?

Answer 7

4

Question 8

Each quarter acts as?

Answer 8

an independent factory

Question 9

There are more than ________ alveoli in each quarter that are arranged in the forms of lobules.

Answer 9

There are more than 200,000 alveoli in each quarter that are arranged in the forms of lobules.

Question 10

Dairy cows starts production of colostrum nearly pre & post parturition for ___-___ days followed by milk production for ~___ days

Answer 10

3,5, 305

Question 11

At ___ _____ of age is when a cow has her first offspring.

Answer 11

At 2 years of age is when a cow has her first offspring.

Question 12

Colostrum is secreted within the first ___days, followed by regular milk for ___ months

Answer 12

Colostrum is secreted within the first 5 days, followed by regular milk for 10 months

Question 13

Is colostrum milk?

Answer 13

No, it is highly concentrated dry matter composed of proteins including Ab and vitamins

Its water composition is very low, around 71%.

Question 14

Milk is full of water (____%) followed by
- carbohydrate (_____%) > fat (____%) > protein (___%) > mineral &vitamins (____%)

Answer 14

Milk is full of water (87%) followed by
- carbohydrate (4.9%) > fat (3.4%) > protein (3.3%) > mineral &vitamins (1.4%)

Question 15

The fat component of milk has more than 400 different fatty acids arranged in 3 broad categories. Polyunsat = omega fatty acids such as omega 3
Fat is really important in diet b/c we get cream, butter, ghee, and different levels of milk (%)

Question 16

There are two types of proteins in milk

Answer 16

based on solubility in water
water soluble = whey
Nonsoluble: majority: 80% of proteins are insoluble. important for cheese industry (called casein proteins)

Question 17

Vitamins in milk?

Answer 17

B12, B2, rich in Ca++ and Phosphorous

Question 18

pH of milk ?

Answer 18

Naturally in pH danger zone
6.5-6.7
microorganisms love this environment

Question 19

How do you know that milk is sanitary?

Answer 19

Measure cells: somatic cells and bacterial cells

Question 20

What are the seven major parameters checked in raw milk production?

Answer 20

Question 21

Regulated milk must have:

Answer 21

1. 87% water,
2. > 3.25% fat,
3. > 8.25% non-fat solids

If do not have this? Adulterated/contaminated

Question 22

llegal to sale milk with
SCC counts above the
set cu-off value by
federal regulators

Answer 22

> 750,000

Get prize for lowest somatic cell count

Question 23

standard plate count of bacteria in milk must be < 100, 000 cfu/ml…… above this value is illegal to sale

Question 24

Take 100 ml of milk, serially dilute in test tubes, swab 1 ml on agar plates, culture for 2 days at 32 degrees, count # of colonies that grew. This is used for regulating bacterial levels in milk.

Question 25

Also check refrigerated milk bacteria too.

Answer 25

Do same thing as above by 12.8 degrees Celcius

Question 26

Pasteurized milk - bacterial check

Answer 26

take sample of milk, heat it at 60 degrees, serially dilute in culture. if observe bacteria in culture = bad

Question 27

How to check for fecal bacteria?

Answer 27

E.coli, enterobactera, citrobacter, etc. Fecal bacteria that means the milk is contaminated with feces of animal Swab milk on selective media, maconkey agar. If find above certain limit they do not buy it.

Question 28

Question 29

Illegal to sale milk with SCC & SPC counts above the set cu-off value by federal regulators

Answer 29

Question 30

Organoleptic quality (Flavor, taste, appearance) of milk must be: 1. Color: normal milk is whitish 2. Odor: should not have off-odor 3. Taste: normal milk is pleasantly sweet 4. Consistency: normal milk is liquid but not watery

Question 31

If there is silage, it smells like silage.

Answer 31

Question 32

There are 5 compounds in milk.

Answer 32

Water, Sugar (lactose), protein, fat, vitamins, minerals If milk is contaminated with bacteria --> eat lactose --> lactic acid --> sour milk

Question 33

Milk tastes cooked when?

Answer 33

It is too pasteurized

Question 34

Milk becomes flat when?

Answer 34

They add water

Question 35

Milk tastes rancid when?

Answer 35

Fat part of milk is converted by microorganisms

Question 36

If pH changes from 6.5 or above and below this range, milk is?

Answer 36

Not normal

Question 37

How do you grade milk?

Answer 37

Composition somatic cell count bacterial count organoleptic The following criteria are used in milk grading 1. Chemical constituents of milk – 87% water, > 3.25% fat, > 8.25% non-fat 2. Load of bacteria count in the milk 3. Bulk tank somatic cell count (udder health or mastitis) 4. Organoleptic features of milk – whitish color, pleasantly sweet and clean with no aftertaste

Question 38

What are the grades of milk in the U.S.?

Answer 38

Three types of milk grades based on bacteria count in the milk 1. Certified milk: ≤ 10,000 cfu/ml bacteria 2. Grade A milk: ≤ 100,000 cfu/ml bacteria 3. Grade B milk: ≤ 500,000 cfu/ml bacteria

Question 39

Certified milk is the best milk

Question 40

Fecal bacteria is allowed in Grade A milk, e.g e.cli

Question 41

Grade B is the lowest quality, up to 1 million somatic cell count and total bacteria count. we do not drink this milk, it is illegal

Question 42

Grade A is used for cheese

Question 43

Question 44

Milk composition manipulation to form a new dairy product first by pasteurization (heating) & cooling followed by separation, standardization or fermentation

Question 45

Question 46

What is are the four kinds of milk pasteurization?

Answer 46

pasteurization usd to be at 63 most common is high temperature short time at ? for 20 seconds. make milk in can, canned serilization at 120 degrees celsius. short ultra: only expose for 2 seconds; this is the most efficient one, gives shelf life of about half a year. we can also 72 --> liquid cheese and yogurt

Question 47

What are the basic steps in milk processing is separating its components apart?

Answer 47

Question 48

How do you sort milk components by nano-pore membrane technology?

Answer 48

NF = nanofiltration; scoop lactose and salt 1 = fat 10 um = proteins 1 um = lactose

Question 49

How is milk processed?

Answer 49

Question 50

How is cheese produced?

Answer 50

Heat up to 32 degrees Add bacteria (Lactococcusl, striptococcus termophilis) - Incubate with milk Add renit (cuts caseins in milk) for 30 min Increase temp to 38 max so it coagulates remove liquid part once coagulated knead the milk add salt cut ? put in storage to make cheese; when ripened you can sell

Question 51

By playing with water, you ma have?

Answer 51

hWhole milk evaportated canned milk where remove60% water Sweetended condensed milk with ? Milk powder Can play with fat cimponent to make cream, ice cream, butter, ghee (pure fat)

Question 52

Question 53

Which milk products are more susceptible to pathogens?

Answer 53

Cheese b/c it is a low quality milk used - major pathogens: listeria monocytognees, e.coli, salmonella, fungus yeasts, Milk is second

Question 54