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LIPIDS. Our plan for the day…. Good things about “fat” Bad things about “fat” Lipid Chemistry (ugh) Carbon chains can be saturated or unsaturated, cis or trans Problems with saturated and trans fatty acids. Good Things About Fats. Concentrated energy source
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LIPIDS Dr. Thomas J. Montville
Our plan for the day… • Good things about “fat” • Bad things about “fat” • Lipid Chemistry (ugh) • Carbon chains can be saturated or unsaturated, cis or trans • Problems with saturated and trans fatty acids Dr. Thomas J. Montville
Good Things About Fats • Concentrated energy source • Stores energy for long term use (fat cells) • Flavor carrier • Heat Transfer - frying • Imparts texture – plasticity, flakiness • Mouthfeel – creamy, smooth Dr. Thomas J. Montville
More good things about fat • Essential fatty acids (linoleic, linolenic) • Phase transition (solid ↔ liquid) • Carries fat soluble (A,D,E,K) vitamins • Satiety- gastric inhibitory protein • Major component of membranes Dr. Thomas J. Montville
Bad Things About Fat • Makes you fat! • Heart disease, high blood pressure, cancer • Unsaturated fats are reactive free radicals Dr. Thomas J. Montville
Stop and discuss carbon chemistry Dr. Thomas J. Montville
Fat Structure Fatty acids are either saturated, monounsaturated (contain one C=C double bond) or polyunsaturated (contain two or more C=C double bonds) Saturated fatty acids stack closely and are more solid. Unsaturated fatty acids are more fluid. “Hydrogenating” unsaturated fatty acids makes them more rigid. Dr. Thomas J. Montville
Fat Structure 1 Saturated Fat – Primarily animal sources: meat, poultry, milk, butter, cheese, egg yolk, lard Plant Sources: chocolate, coconut, coconut oil, palm oil, vegetable shortening 3. Polyunsaturated Fat - Primarily plant sources: vegetable oils (corn, safflower, soybean, sunflower, canola, etc.), margarine (most), mayonnaise, certain nuts (almonds, filberts, pecans, walnuts) Animal Sources: fish Dr. Thomas J. Montville
Fat Structure 2. Monounsaturated Fat Sources: avocado, peanuts, peanut butter, olive/olive oil Dr. Thomas J. Montville
Trans fats, what were they thinking? Polyunsaturated > monounsaturated Dr. Thomas J. Montville
Trans Fats • Time Article “Fessing Up to Fats” Dr. Thomas J. Montville
Trans Fat • Men’s Health Article “The Hidden Killer” • “It’s a fat that’s difficult to digest so it increases the amount of bad cholesterol in your blood and can dramatically boost your risk of heart disease. If saturated animal fats are unhealthy, trans fats are far worse.” • “You’re almost better off eating butter and bacon.” • “Harvard scientists estimate that trans fats may contribute to more than 30,000 premature deaths per year.” Dr. Thomas J. Montville
Linolenic Acids Alpha – linolenic acid (omega 3) Structure of omega-3 fatty acids and omega-6 fatty acids. These fatty acids are defined by the location of the first double bond. Dr. Thomas J. Montville
Summary of Fats Dr. Thomas J. Montville
Nutritional Overview of Lipids • Classification • Triglycerides – 95% of dietary fat • 1 glycerol + 3 fatty acids • Fatty acids • Short, medium, or long chains • Saturated (no double bonds) • Monounsaturated (one double bond) • Polyunsaturated (> one double bond) • Omega 3 • Omega 6 • Cholesterol • Phospholipids • Energy value 9kcal/g Dr. Thomas J. Montville
Nutritional Overview • Functions • Provide energy • Serve as energy reserve • Assist in transport and adsorption of fat-soluble vitamins • Serve as source of essential fatty acids • Insulate and protect organs • Maintain cell walls and play role in making Vitamin D Dr. Thomas J. Montville
Nutritional Overview • Food Sources • Oils, sauces, spreads, butter • Meat, poultry, fish, eggs, nuts (fish oil for omega 3s) • Milk, cheese, dairy • Breads cereals and grains with added fats • Recommended Intake • Less than or equal to 30% of calories from total fat • Less than or equal to 10% of calories from saturated fat • No more than 300 mg cholesterol Dr. Thomas J. Montville
Fats In Food • Milk: (8 oz. serving) • Whole: [3-4 % (legal 3.2%)] 150Kcal • 2%: 120 Kcal • 1%: 100 Kcal • Skim: [<.5%] 90 Kcal • Cream: • Heavy (Whipping): 36% • Light: 18% • ½ & ½ : 10.5% • Others: • Mayo: 65% oil, vinegar, sugar, salt, egg yolk • Salad Dressing: 40% oil Dr. Thomas J. Montville
Fat Substitutes • Simplex • Egg white and milk protein • very small 0.1 – 0.3uM • microencapsulated • Oatrium – from oat bran or flour • Avicel – microcrystalline cellulose (from wood) (0 calories) • Olestra (Olean) polyester sucrose Dr. Thomas J. Montville
Fat Substitutes • Olestra • Indigestible • Lack of ADEK • Digestive issues • Anal leakage Dr. Thomas J. Montville
“On the seventh day of Olestra…” Dr. Thomas J. Montville
http://www.zug.com/pranks/olestra + = Day 1 Day 3 Day 5 Day 7 Dr. Thomas J. Montville
Take Home: Fats, Oils, Lipids • Good things about fats • Concentrated source of energy 9 cal/g • Flavor carrier • Imparts texture • Imparts mouthfeel, phase transiition • Carries fat soluble vitamins, ADEK • Major component of membranes • Satiety Dr. Thomas J. Montville
Take Home: Fats, Oils, Lipids • Bad things about fats: • Saturated – solid, animal, leads to cholesterol • Unsaturated, polyester sucrose, non-digestible, loss of ADEK • Makes you fat • Coronary disease • Heart disease • Cancer Dr. Thomas J. Montville
Take Home Points • Know the good and bad characteristics of fats and oils • Saturated vs. unsaturated • where found, why used • cis vs. trans • Fat in Food • How much? • What foods? • Different types of oil (general) • Fat free does not equal calorie free • Fat Substitutes Dr. Thomas J. Montville