Food Labels I Objective: Identify ingredients that contribute calories of different types of carbohydrates, different lipids, and protein.

I. Common Carbs Simple sugars: Other Carb: Starch Monosaccharides fructose glucose galactose Disaccharides sucrose lactose maltose Other Carb: Starch Dietary Fiber: Cellulose Image from widimedia: http://commons.wikimedia.org/wiki/File:Cellulose_Haworth.svg , and http://upload.wikimedia.org/wikipedia/commons/b/b7/Sucrose_Chemical_Structure.jpg

Rules to Recognize Carbohydrates: Plants Simple sugars: Obvious names [Fructose, Sucrose (table sugar), lactose], corn syrup (enzymatic breakdown of corn starch), high-fructose corn syrup (undergone further enzymatic processing to convert glucose into fructose). Rule: -ose as an ending, sweet Other Carb: Starch Rule: long-term energy storage for plants (roots, seeds), digested by hydrolysis in germinating seeds to provide glucose energy Dietary Fiber: Cellulose Rule: structural component of cell walls of plants

Digestion of Carbohydrates Any carbohydrate bigger than monosaccharides too big to cross into the blood stream Hydrolysis enzymes are located in mouth, and small intestine. One enzyme (proteins) for each disaccharide. Enzyme amylase Starch glucose Enzyme sucrase Sucrose glucose + fructose Enzyme lactase Lactose glucose + galactose Lactase Image from wikimedia: http://commons.wikimedia.org/wiki/File:Lactose_etc.png

Clicker Question 1 Which of the following contains mostly carbohydrates that are monosaccharides? Nonfat dry milk Sugar Fructose Powered cellulose Modified corn starch

Clicker Question 2 Which of the following does NOT contain complex carbohydrate? Nonfat dry milk Corn bran Soy fiber Modified corn starch Powdered cellulose

Polysaccharides (Complex) Starch Glycogen Cellulose

Digestion of Cellulose Glucose linked differently in starch and cellulose Starch: Cellulose: Cellulose (fiber) calorie free because is we do not make digestive enzymes that can recognize the bonds. Cellulose image from: http://upload.wikimedia.org/wikipedia/commons/3/31/Fibres_de_cellulose.png Starch image from wikimedia commons: http://commons.wikimedia.org/wiki/File:Poly-%281-4%29-alpha-D-Glucose.svg

Clicker Question 3 Which of the following provides no calories because it is indigestible to humans? Nonfat dry milk Sugar Fructose Spinach Modified corn starch

Health and Carbohydrates We need about 150g a day to live. We exhaust supplies of glycogen in about 12 hours.(Good thing for FAT!) Dietary Guidelines: 50-55% total Calories come from carbs. Majority should be complex, not simple sugars Currently 40-50% are from sugars Sugars lack fiber and vitamins

KLONDIKE 1. Which one of these two Klondike bars would you want to eat if you were on a low fat diet? Which one do you really want to eat? 2. What is the biggest substantial difference between the two? 3. How do they accomplish this by changing ingredients?

Clicker Question 4 Which of the following ingredients contributes fat to the Klondike bar? Non-fat milk Milkfat Vegetable oils Sugar Cellulose gum

II. Two Major Lipids in food Triglycerides (fats and oils) Cholesterol Phospholipids are found in all cell membranes, but not listed on food label.

1. Triglycerides glycerol 3 fatty acids Image from wikimedia: http://upload.wikimedia.org/wikipedia/commons/6/64/Trimyristin-3D-vdW.png

Differences Between Fatty Acids FATS Solid at room temperature Enriched in animal sources +coco & palm Saturated in hydrogens OILS Liquid at room temperature Enriched in plant sources like seeds Unsaturated Stearic acid image from: http://commons.wikimedia.org/wiki/File:Ethyl_Stearate.png Linoleic acid image from: http://commons.wikimedia.org/wiki/File:Linolic-acid-3D-vdW.png Saturated fatty acid from: http://upload.wikimedia.org/wikipedia/commons/c/c3/Fatty_acids.png

Unsaturated Fatty acids Monounsaturated: one C=C olive, canola, nut oils Polyunsaturated: more than one C=C, corn safflower, soy oils Hydrogenated: oils made solid by breaking C=C bonds and replacing with H (Hydrogenation) Partially hydrogenated – margarine. Converts Cis to Trans fats

Fats/Oils & Diet Fat is the most concentrated energy source. Absorption of fat soluble vitamins. Flavor and satiety. Essential fatty acids (linoleic, polyunsaturated) required, not made by our bodies. Absence leads to problems with blood clotting, hormone synthesis and muscle function. RDA: 25-35% Calories from fats and oils 10% is too little 40-50% found in average American diet, much of it saturated fats with associated cholesterol.

Clicker Question 6 Which of the following ingredients contributes saturated fat to the Klondike bar? Milkfat Vegetable oils Sugar Cellulose gum

2. Steroids Four fused rings of carbon steroid hormones: estrogen, testosterone cholesterol: vital component of animal cell membranes, starting material for steroid hormone synthesis testosterone Progesterone image from wikimedia: http://commons.wikimedia.org/wiki/File:20-alpha-dihydroprogesterone.svg Testosterone image from:http://commons.wikimedia.org/wiki/File:Testosterone.PNG Cholesterol from: http://commons.wikimedia.org/wiki/File:Cholesterol.png cholesterol progesterone

Cholesterol in blood is packaged with protein 1. Bad: LDL (low density lipoprotein) carrying cholesterol to cells, <130 2. Good: HDL (high density lipoprotein) carrying cholesterol to liver for elimination. >50 Overall cholesterol <200 Lipoprotein from: http://upload.wikimedia.org/wikipedia/commons/9/92/Structure_of_a_Lipoprotein.jpg Bad versus good cholesterol from: http://hubpages.com/hub/ldlcholesterol

Clicker Question 8 Which of the following ingredients contributes cholesterol? Peanut butter Vegetable oil Beef French fries (fried in corn oil)

III. Proteins in food 20 different amino acids We can manufacture most. 8 Essential Amino Acids can’t be synthesized by our bodies, but must be found in diet. Rule: All living organisms have protein, but all 8 essential amino acids are present in animal protein (meat, eggs, milk), vegetable protein may lack some.

Clicker Question 9 McDonald’s French fries contain 3g of protein. Which of the following ingredients would contribute calories from protein? Potatoes Vegetable oil Dextrose Salt Hydrogenated soybean oil