1. MILK

2. Objectives Define the term “milk”
Describe quality control during the production of milk and milk products
Explain pasteurization and homogenization
Identify three methods of pasteurization
Describe the “solids” composition of milk
Discuss the separation of butterfat and its use
List four beverage milk products
Describe butter
Name 5 concentrated or dried dairy products
List the steps in the cheese making process
Identify 3 bacteria used to produce dairy products
Name 5 fermented dairy products
List the steps in making and ice cream and make ice cream
Describe the USDA quality grade shields

3. Terms To Know Buttermilk Churning Coalesce Curd HTST Lipolysis LTLT
Rennet
Ripening
Ropey
Solids-not-fat
Standard plate count (SPC)
standardized
Ropey
Solids-not-fat
Standard plate count (SPC)
standardized
Thermization
UHT
Ultrapasteurization
Vaccum evaporation
Whey

4. Introduction Milk: the first food for young mammals
Provides high quality protein, vitamins and minerals and is a source of energy
Worldwide many mammilian species are used to produce milk and milk products
Goats, sheep, horses, yaks
However, our focus will be on milk from dairy cows

5. Fluid Milk

6. Fluid Milk
Collodial dispersion of the protein caesin and the whey proteins. It is an emulsion with fat globules suspeneded in the water phase
Composed mainly of water
87-89%
Milk solids make up the other 12-13%
Solids include the carbs, lactose, fat, protein and minerals
Solids-not-fat
Excludes the fat and includes the caesin, whey, lactose, proteins, minerals

7. Production Practices Fewer cows are producing more milk
Daries are becoming larger
In major production areas daries are 1,000 cows or more
Milk fresh from the cow is virtually sterile
Post handling must maintain the milks nutritional value and prevent deterioration caused by physical and biological changes
Equipement must be maintained to government and industry standards

8. Production Practices Cows are milked twice a day
Some farms milk 3-4 times/day
Milk is immediately cooled from the body temperture of the cow to below 41 degrees F
It is then stored at the farm under refrigeration until it is picked up by tanker trucks at least every other day
A sample of the milk is collected at this time for later lab analysis

9. Quality Control On the farm
Inspectors monitor herd health, farm water supply, sanitation, milk temperture, holding times, bacteria counts
Violations of health standards result in heavy penalties up to and including suspension from business
Inspections occur both at the farm and processing plants on a regular on-going basis
Inspectors have full authority to suspend plant operations in order to conduct detailed examinations of all equipment, facilities and products
The dairy industry works hard to ensure that they comply with or exceed all regulations

10. Quality Control Finished dairy products
Tested regularly by state inspectors to ensure compliance with
Standards of Identity
Refers to criteria such as mouisture, butterfat, protein content
Purity
Refers to pathogens and residues criteria
The Food and Drug Administration (FDA) sets the standards of identity for beverage milk products

11. Processing
When milk arrives at the plant it is checked to make sure that it meets the standards for temperture, total acidity, flavor, odor, tanker cleanliness and absence of antibiotics
Butterfat and solids-not-fat content is analyzed
These amounts will vary with the feed, breed of cow and time of year
These are also used along with the volume to determine what the producer will be paid
Once the milk passes these receiving test it is pumped into large refrigerated silos

12. Pasteurizing
Heating the raw milk to kill all pathogenic microoranisms that may be present
Not sterilization
After pasteurization some harmless bacteria may still be present
these are the bacteria that cause milk to go sour
Refrigeration is the best way to slow the growth of these organisims

13. Pasteurizing Low Temperture Longer Time (LTLT)
Heats milk to at least 145 degrees F for at least 30 minutes
Can cause a “cooked” flavor
Not used by some milk plants for fluid milk products
High Temperture/Short Time (HTST)
Heats milk to at least 161 degrees F for at least 15 seconds
Milk is immediately cooled to below 40 degrees F and packaged in plastic jugs or plastic coated cartons
Ultrapasteurization
Heating milk to 280 degrees F or higher for 2 seconds followed by rapid cooling to 45 degrees or less
Ultrahigh Temperture Processing
Sterilizes the milk
Heats it to degrees for 2 to 6 seconds
Milk is aseptically packaged and does not require refrigeration until it is opened

14. Butterfat Several different types of product
Whole milk, 2%, 1%, nonfat, Half & Half
Seperated using separator that separates the cream and skim portions of the milk
For example: During the separation of whole milk two streams are produced: the fat-depleted stream, which the above mentioned beverage milks are made of; skim milk for evaporation and/or drying and the fat-rich stream, the cream

15. Butterfat: Cream Comes from the separator with a fat content of 35-45%
Used for further processing in the dairy industry—ice cream, butter

16. Homogenization Prevents the cream from rising to the top
A “homogenizer” forces milk under high pressuure through a valve that breaks up butterfat globules to such a small size that they will not coalesce (stick together)
Does not affect the nutrion or quality

17. Beverage Milk Most raw milk fat content is 4% or higher
Most beverage milk is 3.4%
Lower fat contents- 2%, 1%, Skim
These products are produced by partial or complete skimming and then adding cream back to achieve the final desired fat content

18. Nutritional Qualities
Vitamins may be added
A & D most often due to their loss
A during fat separation and heating
D because it is not present in milk
Supplemeted in the form of a water-soluble emulsion
Many states have milk standards that require the addition of milk solids
These represent the natural mineral, protein, and sugar portion of nonfat dry milk

19. Quality Control Numerous test on raw and paterurized product
Microbial organisims are tested for using the standard plate count (SPC) and ropey milk test
Equipment used to analyze butterfat and solids-not-fat is calibrated on a regular basis to ensure consistency
All products have a sell-by date
Samples of the products packaged each day are saved to confirm they maintain their freshness 7 days after the sell-by date

20. Packaging
Once milk is separated, standardized, homogenized and pasteurized it is held below 40 degrees F
Then it is packaged into gallon, ½ gallon, quart, pint and half pint containers
Packaging machines are maintained under strict standards
All equipment is washed daily
Automatic clean-in-place systems guarantee consistent sanitation with minimum manual handling to reduce the risk of contamination
Once packaged the products are conveyored to cold storage where they are stored for a short time before being shipped to supermarkets where they are kept in cold storage or refrigerated display cases

21. Milk Products and By-Products

22. Milk Products and By-Products
Include
Butter
Concentrated and dried milk
Cheese
Whey products
Yogurt
Fermented products
Ice Cream

23. Butter Made by churning pasteurized cream
Churning breaks up the fat globule membrane
This breaks the emulsion, fat coalesces and the water (buttermilk) escapes
Federal law requires that it contain at least 80% milkfat, nutritionally butter is a fat.
Salt and coloring may be added
Today commercial butter making is a product of knowledge and experience gained over the years

24. Butter Make-Up Normal Salted Butter Fat 80-82% Water 15.6-17.6%
Proteins, Calcium, Phosphorous 1.2%
Also contains fat soluble vitamins A, D, E

25. Butter Should have uniform color Be dense Taste clean
Water should be dispersed in fine droplets so that the butter looks dry
Consistency should be smooth so that it is easy to spread and melts readily on the tongue

26. Making Butter From storage tanks the cream goes to pasteurization
This destroys enzymes and microorganisms that would impair the keeping quality of the butter
Next, ripening
Here the cream is subject to a program of heat treatments designed to give the fat the necessary crystaline structure so it solidifies on cooling
Takes hours
Churning
Cream is violently agitated
This breaks down the fat globules, causing the fat to coagulate into butter grains, leaving the liquid part (buttermilk)
Butter is salted and worked to ensure even distribution
Packaged
Sent to cold storage

27. Butter Churns From the Past

28. Today’s Butter Churn

29. Concentrated and Dried Dairy Products
Concentrated products have partial water removal
Dried products have water removed to less than 4%
Benefits of both products are
Increased shelf life
Convenience
Product flexibility
Decreased transportation costs
Storage

30. Concentrated and Dried Dairy Products
Concentrated Products
Evaporated skim or whole milk
Sweetened condensed milk
Condensed buttermilk
Condensed whey
Dried Products
Milk Powder
Whey Powder
Whey Protein concentrates

31. Cheese
Traditionally cheese was made as a way of preserving the nutrients of milk
Cheese- the fresh or ripened product obtained after coagulation and whey seperation of milk, cream, or partly skimmed milk, buttermilk or a mixture of these
THOUSANDS of varieties

32. Cheese Making Steps Treat milk Additives Inoculation and milk ripening
Coagulation
Enzyme
Acid
Heat-acid
Curd Treatment
Cheese ripening

33. Yogurt Semisolid fermented milk product Originated in Bulgaria
Milk from a variety of animals is used in yogurt production but most of the industrialized nations use cow’s milk
Starter culture used in most yogurt production is a blend of Streptococcus salivarius thermophilus (ST) and Lactobacillus delbruekii bulgaricus (LB)

34. Making Yogurt Milk is clarified and separated into cream and skim milk
Standardized to achieve the desired fat content
Various ingredients are blended together in a mix tank equipped with a power funnel and an agitation system
Mixture is then pasteurized
Once the homgenized mix has cooled to an optimum growth temperature, the yogurt starter culture is added

35. Fermented Milk Beverages
Cultured Buttermilk
Once a by-product of butter production, now produced from whole or skim milk
Acidophilus Milk
Traditional milk fermented with LA which is thought to have therapeutic benefits in the gastrointestinal tract
Sour Cream
Others

36. Ice Cream (start) Greater than 10% milk fat by legal definition
As high as 16% fat in some premium ice cream
9-12% milk solids-not-fat
Also contains 12-16% sweeteners-usually a combination of sucrose and glucose-based corn syrup sweeteners
% stabilizers and emulsifiers
55-64% water from the milk or other ingredients
When frozen about half the volume of ice cream is air
All ice cream is made from a basic white mix

37. Basic Steps In Manufacturing Ice Cream
Blending of the mix ingredients
Pasteurization
Homogenization
Aging the mix
Freezing
Packaging
Hardening

38. Quality Products Established by USDA
Grades are used to describe different grades of quality in butter, cheese (Cheddar, Colby, Monterey, Swiss)
FDA established the Grade A designation for fluid milk products, yogurt and cottage cheese
Grade standards are used to
Identify levels of quality
Provide a basis for establishing prices at wholesale
Supply Conumers with a choice of quality levels

39. Milk Substitutes Margarine Frozen desserts Coffee whiteners
Whipped toppings
Soy milk
All are made by combining nondairy fats with certain classes of milk components

40. Reduced Fat Products
Brought on to the market in the effort to reduce calories, saturated fat, cholesterol
When fat is replaced the replacement must perform the same functions as the fat.
It must give the product the same texture or “mouth feel”
Why?
What would consumer repsonse be if it didn’t?

41. Summary Milk provides high quality protein, energy, vitamins, minerals
Dairy industry provides a variety of milk products
USDA and FDA maintain quality standards
Milk is pasteurized to protect consumers against pathogens
Milk is homogenized to keep milk fat in suspension
Butterfat is separated from the milk to be added back in in the desired amounts
Concentrated and dried products increase shelf life and convenience and decrease transportation costs
USDA established grade standards for butter, cheese and instant nonfat dry milk
FDA established grade designations for fluid milk, yogurt, cottage cheese
Only officially graded products carry a grade shield
In an effort to meet consumer demands the food industry has developed milk and milk substitutes and reduced fat products

42. Lab
Making Butter

43. STUDENT ACTIVITY Develop a presentation comparing BUTTER to MARGARINE
Compare their make-up (ie-butter is made from milk fat and margarine is made from vegetable oil)
Compare their healthfullness
Find pictures
Make a poster