Food Science Class
Chapter 16 Notes
Milk Composition
•Water: 88%
•Carbohydrate: 5%
•Fat: 3-4% in Whole Milk
•Protein: 3-4%
•Vitamins and Minerals
Carbohydrates
•Primarily Lactose
•Lactose not as sweet as sucrose
•Lactose is not easily digested.
•When bacteria grow in milk
(fermentation), lactose becomes lactic acid: sour
Milk Fat
•Most Expensive component of milk
•Amount of fat in milk varies with breed
•Carries fat-soluble vitamins and Cholesterol
•Milk Fat separated from Whole Milk at Dairy: Skim
•Added back to make 1%, 2%, and whole milk
•Fat exists in globules.
•Lighter than water, so globules rise to the top (creaming)
•Homogenized milk makes emulsion out of large fat globules
Proteins
•Balanced amino acids, easy to digest
•Soluble Whey proteins
•Enzymes
•Casein can be coagulated by heat, salt or acid
Vitamins and minerals
•Good source of both water-soluble and fat soluble vitamins
•Riboflavin (light sensitive)
•Vitamin A (fat soluble): fortified in low-fat milk
•Calcium and Phosphorus: 1% of milk
Milk Production
•From Cows, Goats, Sheep
•Amount of Milk fat and quantity of milk varies with breed
•Holstein produces most milk
•Guernsey and Jersey produce highest milk fat
Raw Milk
•Contaminated with bacteria
•Must be refrigerated immediately
–Handled in sanitary manner
Unpasteruized milk
•Must be pasteurized
–Unpasteruized milk is a source of:
•Tuberculosis
•Diptheria
•Salmonellosis
•Typhoid Fever
Transgenic Cows
- Produce pharmaceutical products in milk.
- Makes human lactalbumen for formula for premature infants .
Milk Processing
- Pasteurization destroys 95-99% of pathogenic bacteria in milk
- Increases shelf life of refrigerated milk
- Combination of heat and time minimize breakdown of vitamins and proteins
Homogenization
–Milk passed through small orifice:
–breaks up large fat globules
–Small fat globules formed
–Homogenization can occur before or after
pasteurization
Fortification
•Usually fortified with Vitamin D (optional)
•Lowfat milk must be fortified with Vitamin A
Milk Products:
•Fluid Milk
•Evaporated Milk
•Sweetened Condensed Milk
•Dried Milk
•Cream
•Butter
•Ice Cream
•Cultured/Fermented Milk Products
Cheeses:
Brie and Camembert
BREE and CAMEMBERT.
French decent creamy and pale colored.
Bloomy rind comes from the Penicillium mold which is applied to the surface.
Formed into wheels.
Mozzarella
Origins in Italy.
#1 Cheese used in the food industry.
Curds are kneaded or stretched.
Formed into balls or logs.
White soft elastic tears into strips.
Provolone
A different culture is used in Provolone than mozzarella to make a fuller taste.
Firm texture full flavor more flavor than Mozzarella.
Comes in cannonball shapes.
Colby
Fresh form is known as the favorite treat, CURDS.
Curds are sprayed with cold water and stirred to keep them from knitting together.
Pressed into shape.
Edam and Gouda
Dutch origins.
Wheel or wedge shape.
Wax covering- red, black, or yellow flavoring is indicated by the color.
Light Buttery nutty, with smooth creamy texture.
Cheddar
Aging makes the flavor.
Medium, mild, sharp, and aged.
Interior is usually yellow but can be white.
Exterior can come in three colors, clear = mild, Red suggests medium, Black suggests sharp
Brick
Semi Hard.
Has small and irregular holes.
Sweet, spicy, and nutty flavor.
It gains aroma with age.
Swiss
Origin in Switzerland.
Characterized by Holes.
Flavor is sweet and nut-like.
Baby Swiss is aged less yielding smaller holes.
Parmesan
Origins in Italy.
hard cheese.
Wheel, wedge, or powder.
Available fresh or in the “Can”.
One of the most popular cheeses in the World.
Muenster
Origins in France
semi soft
Orange or white surface; creamy white interior.
Wheels or loafs
MILK PROCESSING
QUALITY GRADES
1. Grade A: fluid milk
2. Grade B: processing/manufacturing (cheese/butter); up to 3 million bacteria/ml
MAJOR PRODUCTS
1.fluid milk: whole milk, 2%, 1%, nonfat milk (less than .5% fat), chocolate milk
2. Fermentation milk(gradeA): cultured buttermilk, yogurt
3. creams (grade A): half & half (11% fat); cream (18%fat); whipping cream(30%fat); coffee cream (18%fat); heavy whipping cream(36%fat); sour cream (18%fat)
4. butter
5. canned milk: evaporated milk (60%water removed); sweetened condensed milk
6.dried milk
7. cheese
8. ice cream
BY-PRODUCTS
1.buttermilk: from butter, dried for baking
2.Whey - from cheese, dried or concentrated
INFLUENCES ON COMPONENTS
•breed of cow
•individual animal
•stage of lactation
•feed
•frequency of milking
•minimum legal composition of whole milk is not less than 3.25% fat and not less than 8.25 solids-not-fat
STEPS IN PROCESSING
1.standardization- adjust fat
2.clarification - remove foreign matter
3.pastuerization - destroy bacteria by heat
4.homogenization - break-up fat globules so the cream doesn’t float to top
5. packaging
6.dating-guaranteed drinkable 7 days beyond date
TRENDS IN CONSUMPTION
- prior to 1945: whole and condensed milk and butter most popular
- after 1945 - more ice cream and cheese
- since 1975 shift from whole to low fat “lite” cheese and from regular ice cream to ice milk
- recently yogurt and frozen yogurt