Transcript Milk and Dairy Foods ANS 232

Milk and Dairy Foods
ANS 232
August 29 and September 5, 2001
John A. Partridge
2100B South Anthony Hall
[email protected]
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)
Table 1. Per Capita Consumption of Milk and Milk Products in Various Countries.
Country
Finland
Norway
Sweden
Netherlands
France
Germany
Austria
Italy
Greece
UK
Ireland
USA
Canada
India
Australia
Japan
Beverage Flavored Fermented
186.3
164.7
145.1
91.2
78.1
70.1
134.1
79.5
54.2
123.4
182.7
96.9
102.6
48.3
96.0
38.0
21.0
6.0
8.6
2.5
1.7
0.7
4.4
4.2
9.7
6.2
Source: International Dairy Federation
37.1
14.7
27.2
19.1
13.6
10.5
9.5
3.3
6.0
3.6
3.2
2.1
3.2
4.2
3.0
7.2
Cheeses
11.8
13.5
15.4
14.9
21.8
16.8
9.6
17.5
22.2
7.5
4.9
10.9
11.7
0.2
8.5
1.0
Cream Butter
1.9
2.4
2.9
1.0
0.9
1.7
1.2
0.8
0.3
0.8
0.7
0.6
1.0
0.0
1.2
0.1
16.0
8.6
8.7
7.2
14.1
14.9
8.8
2.3
2.7
8.4
11.8
3.8
7.8
21.1
6.4
1.1
Gross Chemical Composition.
• Average composition.
87.3% Water
3.7% Fat
3.4% Protein
4.9% Lactose
0.7% Ash
Species
Table 3. Composition of Milk from Different Mammalian Species
(per 100 g fresh milk).
Cow
Human
Water Buffalo
Goat
Donkey
Elephant
Monkey, rhesus
Mouse
Whale
Seal
Protein (g)
3.2
1.1
4.1
2.9
1.9
4.0
1.6
9.0
10.9
10.2
Fat (g) Carbohydrate (g) Energy (kcal)
3.7
4.6
66
4.2
7.0
72
9.0
4.8
118
3.8
4.7
67
0.6
6.1
38
5.0
5.3
85
4.0
7.0
73
13.1
3.0
171
42.3
1.3
443
49.4
0.1
502
Cow's Milk
Breed
Table 4. Gross composition of milk of various breeds, g/100g.
Body Wt.
(kg)
Holstein
640
Brown Swiss 640
Ayrshire
520
Guernsey
500
Jersey
430
Shorthorn
530
Milk Yield
(kg)
7360
6100
5760
5270
5060
5370
Fat Protein
(%)
(%)
3.54
3.29
3.99
3.64
3.95
3.48
4.72
3.75
5.13
3.98
4.0
3.32
Lactose
(%)
4.68
4.94
4.60
4.71
4.83
4.89
Ash
(%)
0.72
0.74
0.72
0.76
0.77
0.73
Total Solids
(%)
12.16
13.08
12.77
14.04
14.42
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.!)
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
Facilities and Equipment
• Types of milking systems
– Parlors
– Around the barn
– Bucket
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)
IV. Milk Processing
• Filtering
• Storage (always below 4 C to prevent outgrowth
of Staph. aureus)
• Centrifugal Processes
• Pasteurization
• Homogenization
• Cooling
• Packaging
• Storage and Distribution
Phase I - Preparations
• Sampling
– Manhole with dipper
» Odor and appearance
» Lab sample for acceptance
– In-line sampler
» Inventory & quality control
Co-mingled sample at the plant
Individual farm samples for
antibiotics, composition, somatic
cell and bacteria counts
Phase II - Unloading
• Vents open before pumping commences
$$$$
• High capacity centrifugal pumps
– Up to 600 gallons per minute
• Filtration and/or clarification - optional
Typical Receiving Operations
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.
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
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.
Milk Storage Regulatory Requirements
• Cleaned when emptied.
• Must be emptied at least every 72 hours.
• >24 hours in tank
– 7-day temperature recording device
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.
Plate Heat Exchanger
High-Temperature, Short-Time Pasteurizer
Centrifugal processes.
Separation
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
Raw Milk
( 3-20m globules)
Homogenized milk
( <2m globules)
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)
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
Butter and Powder
•
•
•
•
•
Butter
Whole milk Powder
Non Fat Dry Milk (NFDM) Powder
Specialty Powders
Evaporated milk
Cheese
Color is added to the milk and allowed
to mix thoroughly.
Rennet is used to coagulate the curd and to separate
the whey, or watery portion of milk, from the solids.
After addition of the rennet, the milk is allowed to sit
undisturbed. The resulting curd is tested with a knife.
The curds are stirred as they are heated
in a cooking step.
The cut curds are allowed to rest so the culture can
grow. The pieces are turned every 15 minutes.
The cheese molds are filled in preparation
for pressing.
Pressed, unripened cheese.
Automated Cheddar Cheese Manufacture
Dairy Processing Handbook
Cheese Classification
• Fresh Cheeses
• Mold Ripened
– Cottage, Cream
– Blue, Camembert
– Acid coagulation
• Bacteria Smear
• Bacterial w/o Eyes
– Limburger, Muenster
– Rennet Coagulation
• Pasta Filata (Pulled Curd)
– Cheddar, Colby, Jack
– Mozzarella, Provalone
• Bacterial w/ Eyes
– Carbon Dioxide, Propionic
Acid
– Swiss, Dagano
Cheese and Related Products
cont’d
• Pasteurized Processed
– American Slices
– Velvetta
• Cold Pack
– Chocolate Cheese
– Wispread
• Whey
– Whey powder
– Whey protein concentrate
Fermented Dairy Foods
• Yogurt
– fob vs prestirred
– Spoonable vs drinkable
– Probiotic Cultures
• Buttermilk
• Sour Cream
– Non-fat?
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 ( <7.5% and >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
Ice Cream Ingredients
•
•
•
•
•
•
•
•
Water
Milk-Solids-Not-Fat
Butterfat
Sweetener
Emulsifier
Stabilizer
Flavorings
Colors
The Freezing Process
• Scraped Surface Heat Exchange
– Batch
– Continuous
• Quality Attributes
– Ice crystal size
– Overrun
– Heat shock