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LIPIDS

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  1. LIPIDS Dr. Thomas J. Montville

  2. 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

  3. 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

  4. 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

  5. Bad Things About Fat • Makes you fat! • Heart disease, high blood pressure, cancer • Unsaturated fats are reactive free radicals Dr. Thomas J. Montville

  6. Stop and discuss carbon chemistry Dr. Thomas J. Montville

  7. 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

  8. 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

  9. Fat Structure 2. Monounsaturated Fat Sources: avocado, peanuts, peanut butter, olive/olive oil Dr. Thomas J. Montville

  10. Trans fats, what were they thinking? Polyunsaturated > monounsaturated Dr. Thomas J. Montville

  11. Trans Fats • Time Article “Fessing Up to Fats” Dr. Thomas J. Montville

  12. 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

  13. 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

  14. Summary of Fats Dr. Thomas J. Montville

  15. 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

  16. 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

  17. 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

  18. 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

  19. Dr. Thomas J. Montville

  20. 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

  21. Fat Substitutes • Olestra • Indigestible • Lack of ADEK • Digestive issues • Anal leakage Dr. Thomas J. Montville

  22. “On the seventh day of Olestra…” Dr. Thomas J. Montville

  23. http://www.zug.com/pranks/olestra + = Day 1 Day 3 Day 5 Day 7 Dr. Thomas J. Montville

  24. 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

  25. 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

  26. 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