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Flashcards in Milk and Dairy Deck (143)
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1

What countries are the top 3 milk producers?

1. USA
2. India
3. China

2

The top 2 producers of milk among Canadian provinces are:

Ontario, Quebec

3

Milk is defined as:

fluid from mammary glands of mammals, produced for the purpose of feeding their young

4

The most produced type of milk is ___, followed by ___, ___, and ____.

Cow; buffalo, goat, sheep

5

What hormone plays a major role in milk production and release?
What hormone supplement may be given to lactating cows to increase production?

oxytocin

bovine somatotropin

6

List the main components of (whole) bovine milk in increasing proportion:

vit&minerals < protein (whey < casein) < fat < sugar

7

the 3 major dairy companies in Quebec:

Saputo
Parmalait
Agropur

8

Describe the general process of milk production in the mammal: (6)

1. oxytocin bind to secretory cells of ALVEOLUS
2. fluid enters lumen of alveolus
3. fat globules, proteins, lactose synthesized and secreted by SC -> added to milk
4. albumin and immunoglobulins transported from blood and added
5. electrolytes brought in from pumps or channels
6. milk flows into CISTERN -> ready to exit through teat

9

What is the major sugar in milk? Describe its synthesis process.

Lactose
1. Glucose taken into secretory cell
2. some will freely diffuse into golgi
3. Some convert into galactose in lumen (glu -> Glu-P -> UDP-Glu -> UDP-Galactose)
4. UDP-galactose moved into golgi (ACTIVE TRANSPORT)
5. Combined by LACTOSE SYNTHETASE

10

In the production of milk in the mammary gland, what do the secretory cells synthesize and contribute?
What is not synthesized by those cells?

Proteins (most)
Fat globules
Sugar (lactose)

Not made by SC:
albumin
immunoglobins
electrolytes

11

The secretion of lactose into milk will be accompanied by ____, due to _____.

water
osmotic draw

12

The proteins synthesized by alveolar cells are made in the ____ of the cells.

ribosomes

13

the fat globules of milk are produced in the ___ of the ____ cells.

ER
secretory alveolar

14

What is the top dairy breed in Canada?
What are some other types?

Holstein (93%)
Jersey, Ayrshire, Brown swiss

15

What is the average lactation length and amount for cows?

305 days
7000 - 20 000 kg

16

What is bST, and what is it used for? How is it produced?

bovine somatotropin, permitted in some countries to stimulate milk production

produced by transferring gene for hormone production from cow to e. coli -> ferment -> harvest and purify protein hormone

17

How is the secretion by SC of fat globules into milk different from other components such as lactose?

Most components exocytosed: vesicles bud off from golgi, travel to surface and fuse with cell membrane, contents released

Fat globules: brought to cell surface, bud outside, encased in membrane (becomes membrane bound lipid globule)

18

Are milk fat globules high in cholesterol?

No, smallest constituent (2%)

19

True/False: milk fat contains a high level of MAGs.

False: least constituent (0.02-0.04%)

20

The 4 main lipids types in milk fat are: (list in decreasing order)

TAG, DAG, PL, keto-acid glycerides

21

The biggest constituent of a milk fat globule is ____, followed by ______.

protein (41%)
phospho and glyco lipids (30%)

22

What fatty acid is the highest in milk?

palmitic (C16), about 24%

23

What is greater in milk, the amount of short chain FAs or the amount of PUFAs ?

short chain FAs

24

The 3 highest SFAs in milk are:

C16, C14, C18

25

What are the proportions of SFAs, MUFAs, and PUFAs in milk fat?

SFA: 55% (C4 - C18 most common)
MUFA: 19.7%
PUFA: 3.5%

26

The second most common fatty acid in milk is:

oleic acid (C18:1)

27

What are the shorthand chem notations for:
lauric acid
myristic acid
palmitic acid
stearic acid

C12
C14
C16
C18

28

The 3 types of PUFAs in milk:

omega 6, omega 3, CLA (conj. linoleic acid)

29

The phospholipids in milk fat globules are associated with:
Why would this be problematic, and what is done to rectify it?

LIPOPROTEIN LIPASE (enzyme)

during homogenization, membrane is disrupted and enzyme comes into contact with FA -> will hydrolyze and oxidize, make off-flavors (rancidity)
so: need pasteurization (heat treatment) to denature enzyme

30

C18:1 and C16:1 are known as:

oleic acid; palmitoleic acid