Flashcards in Milk and Dairy Deck (143)
What countries are the top 3 milk producers?
The top 2 producers of milk among Canadian provinces are:
Milk is defined as:
fluid from mammary glands of mammals, produced for the purpose of feeding their young
The most produced type of milk is ___, followed by ___, ___, and ____.
Cow; buffalo, goat, sheep
What hormone plays a major role in milk production and release?
What hormone supplement may be given to lactating cows to increase production?
List the main components of (whole) bovine milk in increasing proportion:
vit&minerals < protein (whey < casein) < fat < sugar
the 3 major dairy companies in Quebec:
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
What is the major sugar in milk? Describe its synthesis process.
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
In the production of milk in the mammary gland, what do the secretory cells synthesize and contribute?
What is not synthesized by those cells?
Not made by SC:
The secretion of lactose into milk will be accompanied by ____, due to _____.
The proteins synthesized by alveolar cells are made in the ____ of the cells.
the fat globules of milk are produced in the ___ of the ____ cells.
What is the top dairy breed in Canada?
What are some other types?
Jersey, Ayrshire, Brown swiss
What is the average lactation length and amount for cows?
7000 - 20 000 kg
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
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)
Are milk fat globules high in cholesterol?
No, smallest constituent (2%)
True/False: milk fat contains a high level of MAGs.
False: least constituent (0.02-0.04%)
The 4 main lipids types in milk fat are: (list in decreasing order)
TAG, DAG, PL, keto-acid glycerides
The biggest constituent of a milk fat globule is ____, followed by ______.
phospho and glyco lipids (30%)
What fatty acid is the highest in milk?
palmitic (C16), about 24%
What is greater in milk, the amount of short chain FAs or the amount of PUFAs ?
short chain FAs
The 3 highest SFAs in milk are:
C16, C14, C18
What are the proportions of SFAs, MUFAs, and PUFAs in milk fat?
SFA: 55% (C4 - C18 most common)
The second most common fatty acid in milk is:
oleic acid (C18:1)
What are the shorthand chem notations for:
The 3 types of PUFAs in milk:
omega 6, omega 3, CLA (conj. linoleic acid)
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