Milk and Dairy Foods ANS 232

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Milk and Dairy FoodsANS 232

• August 29 and September 5, 2001
• John A. Partridge
• 2100B South Anthony Hall
• partridg_at_msu.edu

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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)

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Table 1. Per Capita Consumption of Milk and Milk
Products in Various Countries.
Country Beverage
Flavored Fermented Cheeses Cream
Butter Finland 186.3 37.1 11.8
1.9 16.0 Norway 164.7 14.7 13.5 2.4
8.6 Sweden 145.1 27.2 15.4 2.9
8.7 Netherlands 91.2 21.0 19.1 14.9 1.0
7.2 France 78.1 6.0 13.6 21.8
0.9 14.1 Germany 70.1 8.6 10.5 16.8
1.7 14.9 Austria 134.1 2.5 9.5
9.6 1.2 8.8 Italy 79.5
3.3 17.5 0.8 2.3 Greece 54.2
1.7 6.0 22.2 0.3 2.7 UK
123.4 0.7 3.6 7.5 0.8 8.4 Ireland
182.7 3.2 4.9 0.7 11.8 USA
96.9 4.4 2.1 10.9 0.6 3.8 Canada
102.6 4.2 3.2 11.7 1.0 7.8 India
48.3 4.2 0.2 0.0 21.1 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
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Gross Chemical Composition.

• Average composition. 87.3 Water
  3.7 Fat 3.4 Protein 4.9
  Lactose 0.7 Ash

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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
4.2 7.0 72 Water Buffalo 4.1
9.0 4.8 118 Goat 2.9 3.8 4.7
67 Donkey 1.9 0.6 6.1 38 Elephant
4.0 5.0 5.3 85 Monkey, rhesus 1.6
4.0 7.0 73 Mouse 9.0 13.1 3.0
171 Whale 10.9 42.3 1.3 443 Seal 10.2 49.4
0.1 502
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Cow's MilkBreed
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 Swiss 640 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.!)
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Grades of Milk

• Grade A
• Temperaturelt45 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

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Facilities and Equipment

• Types of milking systems
• Parlors
• Around the barn
• Bucket

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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)

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IV. Milk Processing

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

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Phase I - Preparations

• Sampling
• Manhole with dipper
• Odor and appearance
• Lab sample for acceptance
• In-line sampler
• Inventory quality control

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Co-mingled sample at the plant
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Individual farm samples for antibiotics,
composition, somatic cell and bacteria counts
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Phase II - Unloading

• Vents open before pumping commences
• High capacity centrifugal pumps
• Up to 600 gallons per minute
• Filtration and/or clarification - optional

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Typical Receiving Operations
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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.

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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

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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.

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Milk Storage -Regulatory Requirements

• Cleaned when emptied.
• Must be emptied at least every 72 hours.
• gt24 hours in tank
• 7-day temperature recording device

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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.

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Plate Heat Exchanger
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High-Temperature, Short-Time Pasteurizer
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Centrifugal processes.
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Separation
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Homogenization

• Reduction of fat globules from 3-20µm to lt2µm
• 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

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Raw Milk ( 3-20?m globules)
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Homogenized milk ( lt2?m globules)
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Fluid Milk Products

• Whole Milk
• gt3.25 Milkfat gt8.25 Milk-solids-not-fat
  (MSNF)
• Optional except for school milk Vitamin D (400
  IU/Quart)
• Reduced Fat Milk
• 25 reduction in Fat
• Lowfat Milk
• gt 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
• gt 0.5 grams fat per serving, 1 cup
• Vitamin A (2000 IU/Quart)
• Optional except for school milk Vitamin D (400
  IU/Quart)

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Fluid Milk Products

• Heavy Cream
• gt36 milkfat
• Light Whipping Cream
• gt30 but lt36 milkfat
• Light Cream
• gt18 but lt30 milkfat
• Half-and-Half
• gt10.5 but lt18 milkfat

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Butter and Powder

• Butter
• Whole milk Powder
• Non Fat Dry Milk (NFDM) Powder
• Specialty Powders
• Evaporated milk

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Cheese
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Color is added to the milk and allowedto mix
thoroughly.
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Rennet is used to coagulate the curd and to
separate the whey, or watery portion of milk,
from the solids.
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After addition of the rennet, the milk is allowed
to sit undisturbed. The resulting curd is tested
with a knife.
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The curds are stirred as they are heatedin a
cooking step.
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The cut curds are allowed to rest so the culture
can grow. The pieces are turned every 15 minutes.
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The cheese molds are filled in preparation for
pressing.
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Pressed, unripened cheese.
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Automated Cheddar Cheese Manufacture
Dairy Processing Handbook
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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

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Cheese and Related Products contd

• Pasteurized Processed
• American Slices
• Velvetta
• Cold Pack
• Chocolate Cheese
• Wispread
• Whey
• Whey powder
• Whey protein concentrate

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Fermented Dairy Foods

• Yogurt
• fob vs prestirred
• Spoonable vs drinkable
• Probiotic Cultures
• Buttermilk
• Sour Cream
• Non-fat?

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Ice Cream and Frozen Desserts

• Compositional Requirements
• Ice Cream
• gt10 milkfat gt20 total milk solids
• Must weigh gt4.5 lb/gallon
• Must contain gt1.6 lb Total Solids/gallon
• Reduced Fat Ice Cream
• 25 reduction in fat content ( lt7.5 and gt3
  milkfat)
• Lowfat Ice Cream
• 3 g fat per serving (½ cup) (lt3 milkfat)
• Nonfat Ice Cream
• ½ g milkfat per serving (½ cup)
• NLEA vs. Old Standards of Identity

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Ice Cream Ingredients

• Water
• Milk-Solids-Not-Fat
• Butterfat
• Sweetener
• Emulsifier
• Stabilizer
• Flavorings
• Colors

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The Freezing Process

• Scraped Surface Heat Exchange
• Batch
• Continuous
• Quality Attributes
• Ice crystal size
• Overrun
• Heat shock