1. All About Milk FOOD SCIENCE MS. MCGRATH

2. Quick Facts About Milk Pasteurization to kill harmful bacteria, milk is heated through a process called pasteurization Homogenization milk that comes directly from the cow separates into fat (cream) and liquid. To create a smooth, even consistency, milk is homogenized which is the process of removing some of the fat, and breaking down the remaining fat into smaller molecules that remain dispersed in the milk

3. Quick Facts About Milk Growth Hormone hormones are neither added to nor present in milk, however some farmers treat their cows with growth hormone to stimulate milk production Raw Milk unpasteurized milk

4. The Varieties of Milk Milk is available in many varieties: 3.25% (Whole) 2% 1% Skim These percentages represents the amount of fat contained in a serving of milk.

5. The Varieties of Milk – Nutrition Labels 1. Which nutrition label represents whole milk? 2% milk? 1% milk? skim milk? 2. What other interesting fact do you notice on the label?

6. The Varieties of Milk – 3.25% (Whole) Creamy! Whole milk contains 3.5% fat by weight, the same amount found when it leaves the cow. Vitamin D is added to most milk produced to enhance the absorption of calcium.

7. The Varieties of Milk – 2% or 1% (Whole) 2% or 1% milk (also known as reduced-fat or low-fat milk). Fat and calorie levels are reduced in these versions, but they have the same complete nutrient package as whole milk.

8. The Varieties of Milk – Skim Fat-free milk (also known as non-fat or skim milk) has no more than 0.2% milk fat. So it’s the lowest in calories but, again, has just as many nutrients as whole milk.

9. Canada’s Food Guide to Milk How much milk do we need? 3 – 4 servings is suggested, for both females and males teens A serving is a cup (250 mL) Cheeses, puddings, ice cream and yogurt are alternatives to milk

10. The Biochemistry of Milk During adolescence and young adult years, milk supplies the calcium for building bones and teeth In older adults, milk combats bone loss caused by aging

11. The Biochemistry of Milk Milk is 75% water This water is a solvent for over 250 chemical compounds, lactose, water soluble vitamins and trace minerals (minerals the body needs) Milk is therefore known as a colloidal dispersion – it is a solution with particles uniformly distributed

12. The Composition of Milk Milk is a source of: fat (about 3.5%) protein (about 3.5%) carbohydrates (about 5%) vitamins minerals The exact composition of milk depends on the cow’s breed, health and its environment.

13. The Composition of Milk - Proteins The two main proteins found in milk are: 1. Casein – approximately 80% of milk protein 2. Whey – approximately 20% of milk protein

14. The Composition of Milk - Proteins See page 360 1. What is a micelle? 2. What makes milk white? 3. What is the normal acidity for milk? 4. When acid is added to milk does the acidity level increase or decrease? 5. What causes the “lumps” in milk? 6. What are curds? 7. What two liquids can cause curdling? 8. How can you prevent curdling while cooking?