1. Milk and Dairy Foods ANS 232 August 29 and September 5, 2001 John A. Partridge 2100B South Anthony Hall partridg@msu.edu

2. Definition of milk. "The lacteal secretion, practically free from colostrum, obtained by the complete milking of one or more healthy cows, which contains not less then 3.25% of milkfat and not less then 8.25% milk ‑ solids ‑ not ‑ fat.” PMO - Pasteurized Milk Ordinance (Food secreted for newborns)

3. Table 1. Per Capita Consumption of Milk and Milk Products in Various Countries. Country Beverage Flavored Fermented Cheeses Cream Butter Finland186.337.111.8 1.916.0 Norway 164.714.713.5 2.4 8.6 Sweden 145.127.215.4 2.9 8.7 Netherlands 91.221.019.114.9 1.0 7.2 France 78.1 6.013.621.8 0.914.1 Germany 70.1 8.610.516.8 1.714.9 Austria 134.1 2.5 9.5 9.6 1.2 8.8 Italy 79.5 3.317.5 0.8 2.3 Greece 54.2 1.7 6.022.2 0.3 2.7 UK 123.4 0.7 3.6 7.5 0.8 8.4 Ireland 182.7 3.2 4.9 0.711.8 USA 96.9 4.4 2.110.9 0.6 3.8 Canada 102.6 4.2 3.211.7 1.0 7.8 India 48.3 4.2 0.2 0.021.1 Australia 96.0 9.7 3.0 8.5 1.2 6.4 Japan 38.0 6.2 7.2 1.0 0.1 1.1 Source: International Dairy Federation

4. Gross Chemical Composition. Average composition. 87.3% Water 3.7% Fat 3.4% Protein 4.9% Lactose 0.7% Ash

5. Species Table 3. Composition of Milk from Different Mammalian Species (per 100 g fresh milk). Protein (g) Fat (g) Carbohydrate (g) Energy (kcal) Cow 3.2 3.7 4.6 66 Human 1.1 4.27.0 72 Water Buffalo 4.1 9.04.8 118 Goat 2.9 3.8 4.7 67 Donkey 1.9 0.66.1 38 Elephant 4.0 5.0 5.3 85 Monkey, rhesus 1.6 4.07.0 73 Mouse 9.013.1 3.0 171 Whale10.942.31.3 443 Seal10.249.40.1 502

6. Cow's Milk Breed Table 4. Gross composition of milk of various breeds, g/100g. Body Wt. Milk Yield Fat Protein Lactose Ash Total Solids (kg) (kg) (%) (%) (%) (%) (%) Holstein 640 7360 3.54 3.29 4.68 0.72 12.16 Brown Swiss640 6100 3.99 3.64 4.94 0.74 13.08 Ayrshire 520 5760 3.95 3.48 4.60 0.72 12.77 Guernsey 500 5270 4.72 3.75 4.71 0.76 14.04 Jersey 430 5060 5.13 3.98 4.83 0.77 14.42 Shorthorn 530 5370 4.0 3.32 4.89 0.73 12.9 Holstein: 12.16% T.S. x 7360 kg/lactation = 895 kg of total solids produced/lactation (140% of her body wt.!) Jersey: 14.42% T.S. x 5060 kg/lactation = 730 kg of total solids produced/lactation (170% of her body wt.!)

7. Grades of Milk Grade A –Temperature<45 F(7C) in 2 h –Bacteria 100,000/ml (300,000/ml commingled) –Antibiotics.005 IU detection limit (16mm zone) – Somatic cells 1,000,000/ml Grade B or Manufacturing Milk

8. Facilities and Equipment Types of milking systems –Parlors –Around the barn –Bucket

9. Precautions at the producer level. Herd Health –Disease affects milk composition (economic (Ec) issue) –Antibiotics (public health (PH) issue) Added Water (Ec) Pesticides and other chemicals (PH) Aflatoxin and other toxins from natural sources (PH) Sanitation program (PH and Ec)

10. IV.Milk Processing Filtering Storage (always below 4 C to prevent outgrowth of Staph. aureus) Centrifugal Processes Pasteurization Homogenization Cooling Packaging Storage and Distribution

11. Phase I - Preparations Sampling –Manhole with dipper »Odor and appearance »Lab sample for acceptance –In-line sampler »Inventory & quality control

12. Co-mingled sample at the plant

13. Individual farm samples for antibiotics, composition, somatic cell and bacteria counts

14. Phase II - Unloading Vents open before pumping commences $$$$ High capacity centrifugal pumps –Up to 600 gallons per minute Filtration and/or clarification - optional

15. Typical Receiving Operations

16. Phase III - Cleaning the Tanker CIP (Clean-in-Place) –safe –effective Tagged before leaving plant. Pump and exterior of the truck are cleaned while CIP is running. –NOT while milk is unloading.

17. Receiving Tests Titratable Acidity (TA) Direct Microscopic Count (DMC) –Bacteria Screening –Somatic Cell Screening Antibiotic Residue Screening –Beta Lactam (Penicillin family) every load –Others on a random basis

18. Silo Tank Equipment 1. Agitator 2. Manhole 3. Temperature indicator 4. Low-level electrode 5. Pneumatic level indicator 6. High-level electrode Note: Tank vents to the interior of the building.

19. Milk Storage - Regulatory Requirements Cleaned when emptied. Must be emptied at least every 72 hours. >24 hours in tank –7-day temperature recording device

20. Pasteurization –Purposes Destroy pathogens --PRIMARY Destroy spoilage Organisms -- Secondary but very important –Time-temperature relationships Equivalent heat treatments – 145F for 30 m – 161F for 15 s – 191F for 1 s – 212F for.01s –Cooked flavor and creamline –Overprocessing to obtain shelflife improvements may be more detrimental to product than helpful.

21. Plate Heat Exchanger

22. High-Temperature, Short-Time Pasteurizer

23. Centrifugal processes.

24. Separation

25. Homogenization –Reduction of fat globules from 3-20µm to <2µm –Same factors that effect the rate of separation in centrifugal processes differences in densities diameter of particles to be separated residence time viscosity drag forces on particle

26. Raw Milk ( 3-20  m globules)

27. Homogenized milk ( <2  m globules)

28. Fluid Milk Products Whole Milk – >3.25% Milkfat; >8.25% Milk-solids-not-fat (MSNF) –Optional except for school milk: Vitamin D (400 IU/Quart) Reduced Fat Milk –25% reduction in Fat Lowfat Milk – > 3 grams fat per serving, 1 cup –Vitamin A (2000 IU/Quart) –Optional except for school milk: Vitamin D (400 IU/Quart) Non-Fat Milk – > 0.5 grams fat per serving, 1 cup –Vitamin A (2000 IU/Quart) –Optional except for school milk: Vitamin D (400 IU/Quart)

29. Fluid Milk Products Heavy Cream –>36% milkfat Light Whipping Cream –>30% but <36% milkfat Light Cream –>18% but <30% milkfat Half-and-Half –>10.5% but <18% milkfat

30. Butter and Powder Butter Whole milk Powder Non Fat Dry Milk (NFDM) Powder Specialty Powders Evaporated milk

31. Cheese

32. Color is added to the milk and allowed to mix thoroughly.

33. Rennet is used to coagulate the curd and to separate the whey, or watery portion of milk, from the solids.

34. After addition of the rennet, the milk is allowed to sit undisturbed. The resulting curd is tested with a knife.

35. The curds are stirred as they are heated in a cooking step.

36. The cut curds are allowed to rest so the culture can grow. The pieces are turned every 15 minutes.

37. The cheese molds are filled in preparation for pressing.

38. Pressed, unripened cheese.

39. Dairy Processing Handbook Automated Cheddar Cheese Manufacture

40. Cheese Classification Fresh Cheeses –Cottage, Cream – Acid coagulation Bacterial w/o Eyes –Rennet Coagulation –Cheddar, Colby, Jack Bacterial w/ Eyes –Carbon Dioxide, Propionic Acid –Swiss, Dagano Mold Ripened –Blue, Camembert Bacteria Smear –Limburger, Muenster Pasta Filata (Pulled Curd) –Mozzarella, Provalone

41. Cheese and Related Products cont’d Pasteurized Processed –American Slices –Velvetta Cold Pack –Chocolate Cheese –Wispread Whey –Whey powder –Whey protein concentrate

42. Fermented Dairy Foods Yogurt –fob vs prestirred –Spoonable vs drinkable –Probiotic Cultures Buttermilk Sour Cream –Non-fat?

43. Ice Cream and Frozen Desserts Compositional Requirements –Ice Cream >10% milkfat; >20% total milk solids Must weigh >4.5 lb/gallon Must contain >1.6 lb Total Solids/gallon –Reduced Fat Ice Cream 25% reduction in fat content ( 3% milkfat) –Lowfat Ice Cream 3 g fat per serving (½ cup) (<3% milkfat) –Nonfat Ice Cream ½ g milkfat per serving (½ cup) –NLEA vs. Old Standards of Identity

44. Ice Cream Ingredients Water Milk-Solids-Not-Fat Butterfat Sweetener Emulsifier Stabilizer Flavorings Colors

45. The Freezing Process Scraped Surface Heat Exchange –Batch –Continuous Quality Attributes –Ice crystal size –Overrun –Heat shock