Lipids

1. Lipids

2. Lipids (Fats)‏ • Lipids are a group of substances that are relatively insoluble in water • Some of these substances include: • Triglyceride = 95% of all Fats (body fat)‏ • Cholesterol(a fat-like compound occurring in bile, blood, brain and nerve tissue, liver and other parts of the body)‏ Steroid hormones, Transport of Fat, Cell Membranes, Component of Cells

3. Lipids (Fats)‏ Phospholipidssuch as Lecithin • Cell membranes, Transport of Fat • Vitamins A, D, E, K • Bile acids

4. Function of Dietary Fats • Provide taste/flavor qualities to foods • Provide fat soluble nutrients • Provide energy in a concentrated form • Provide satiety

5. Function of Body Fat • Provides a storage form of energy • Provides insulation • Provides protection to internal organs • Provides fat for lactation

6. Triglycerides • 95 % of all fat in Nature, including dietary Fat and Body Fat • Stable condition of Fat for storage • Breaks down during digestion so Free Fatty acids can be absorbed

7. The Chemist’s View of Fatty Acids and Triglycerides • Triglycerides are lipids with three fatty acids attached to a glycerol.

11. Lipids (Fats)‏ A Fat (Based on it’s composition of Fatty Acids) is classified as • Saturated, or Unsaturated • Saturated and unsaturated fats are made up of fatty acids (saturation refers to the number of hydrogen atoms in the fatty acids)‏

12. Lipids (Fats)Saturated Fats A saturated fat acid carries all the hydrogen atoms it can;

13. Fatty Acids: Saturated Fatty acids

14. Lipids (Fats)Saturated Fats • saturated fats are found in whole milk, egg yolks, meat, meat fat, coconut and palm oils, chocolate, margarine, and hydrogenated vegetable oils

15. Something to Think About • What disease did cured ham actually have?

16. Fatty Acids:Unsaturated fatty acids • Unsaturated fats are derived from plants • Monounsaturated fats are found in olive oil and some nuts

17. Fatty Acids:Unsaturated fatty acids Polyunsaturated fats are found primarily in safflower, cottonseed, corn, soybean, and sesame seed oils; salad dressing made from oils; and fatty fish

18. Stearic acid, an 18-carbon saturated fatty acid Oleic acid, an 18-carbon monounsaturated fatty acid Linoleic acid, an 18-carbon polyunsaturated fatty acid

19. Excuse me but which is the one that practically Kills you…..polysaturated or polyunsaturated?

20. Fatty Acids:Unsaturated fatty acids Polyunsaturated fats are found primarily in safflower, cottonseed, corn, soybean, and sesame seed oils; salad dressing made from oils; and fatty fish There are Two different types of Polyunsaturated Fatty Acids. Omega-3-Fatty Acids Omega-6-Fatty Acids

21. The Chemist’s View of Fatty Acids and Triglycerides • Polyunsaturated Fatty Acids • The Location of Double Bonds • The omega number refers to the position of the first double bond. • An omega-3 fatty acid has the location of the double bond in the third position from the end carbon. An example is linolenic acid. • An omega-6 fatty acid has the location of the double bond in the sixth position from the end carbon. An example is linoleic acid.

22. Essential fatty Acids • Linoleic acid is the only essential dietary lipid; it is found in safflower, sunflower, and corn

24. Omega-3 fatty acids • Omega-3 fatty acids are Polyunsaturated Fatty acids classified as essential because they cannot be synthesized in the body; they must be obtained from food. • Important omega-3 fatty acids in human nutrition are: α-linolenic acid(ALA),eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA).

25. Omega-3 fatty acids Health benefits • U.S. FDA gave "qualified health claim" status to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) omega-3 fatty acids, stating that "supportive but not conclusive research shows that consumption of EPA and DHA omega-3 fatty acids may reduce the risk of Coronary Heart Disease

26. Omega-3 fatty acids

27. Omega-3 fatty acids • Fish oils and plant oils are the primary dietary source of omega-3 fatty acids. • Another potential source of omega-3 fatty acids is New Zealand green lipped mussels. • EPA and DHA are found in cold-water fish such as salmon, mackerel, halibut, sardines, and herring. • ALA is found in flaxseeds, flaxseed oil, canola (rapeseed) oil, soybeans, soybean oil, pumpkin seeds, pumpkin seed oil, purslane, perilla seed oil, walnuts, and walnut oil

28. Fats-Dietary Guidelines • Keep total fat intake between 20 to 35 percent of total calories • Most from poly and mono fatty acids (fish, nuts, vegetable oils, etc.)‏ • Consume < 10% of calories from saturated fatty acids, • Consume < 300 mg/day of cholesterol, • Keep trans fatty acid consumption low

29. Fats-Dietary Guidelines • Eat lean, low-fat, or fat-free meat, poultry, dry beans, and milk or milk products • Limit intake of fats, oils, and products high in sat/trans fatty acids

30. Fats and Health Concerns • Diets high in cholesterol and saturated fat are believed to increase the risk of coronary heart disease, some cancers and obesity • Polyunsaturated fatty acid (PUFA) polyunsaturated fats tend to lower blood cholesterol

33. The Chemist’s View of Fatty Acids and Triglycerides • Degree of Unsaturation Revisited • Firmness • Saturated fats are solid at room temperature. • Polyunsaturated fats are liquid at room temperature. • Shorter fatty acid chains are softer at room temperature than longer chains.

35. Something to Think About • If the professor on Gilligan's Island can make a radio out of a coconut, why can't he fix a hole in a boat?

36. The Chemist’s View of Fatty Acids and Triglycerides • Degree of Unsaturation Revisited • Stability • Saturated fat is more resistant to oxidation. • Monounsaturated fat is slightly less susceptible to spoilage. • Polyunsaturated fat spoils most readily. • Protection from rancidity • Sealed in airtight containers away from light • Add antioxidants • Hydrogenation

37. The Chemist’s View of Fatty Acids and Triglycerides • Degree of Unsaturation Revisited • Hydrogenation • Protects against oxidation therefore prolonging shelf life • Alters texture • Trans-Fatty Acids • Changed from cis to trans configuration and act like saturated fats in the body • Heart disease connection is being researched. • Conjugated linoleic acid is a naturally occurring trans fat that may be beneficial to health.

38. What is Trans Fat? • Basically, trans fat is made when manufacturers add hydrogen to vegetable oil--a process called hydrogenation. • Hydrogenation increases the shelf life and flavor stability of foods containing these fats.

40. Trans fat • Trans fat can be found in vegetable shortenings, some margarines, crackers, cookies, snack foods, and other foods made with or fried in partially hydrogenated oils. Unlike other fats, the majority of trans fat is formed when food manufacturers turn liquid oils into solid fats like shortening and hard margarine.

41. Trans fat • Trans fat, like saturated fat and dietary cholesterol, raises the LDL cholesterol that increases your risk for CHD. • Americans consume on average 4 to 5 times as much saturated fat as trans fat in their diets.

42. The Chemist’s View of Phospholipids and Sterols • Phospholipids and sterols have unique chemical structures that allow them to have unique roles in the body. • Sterols have a multiple-ring structure.

43. The Chemist’s View of Phospholipids and Sterols • Phospholipids • Phospholipids in Foods • Phospholipids contain glycerol, two fatty acids and a phosphate group with a molecule of choline. • Used as emulsifiers in food industry • A well-known phospholipid is lecithin. • Food sources of lecithin include eggs, liver, soybeans, wheat germ and peanuts.

45. Do the Alphabet song and Twinkle, Twinkle Little Star have the same tune?

46. Do the Alphabet song and Twinkle, Twinkle Little Star have the same tune? •  Did you just try singing the two songs above?

47. The Chemist’s View of Phospholipids and Sterols • Roles of Phospholipids • Enable transport of lipids across cell membranes • Emulsifiers • Lechithin is made by the liver. Supplements increase energy intake and can cause GI symptoms.

49. The Chemist’s View of Phospholipids and Sterols • Sterols – A well-known sterol is cholesterol. • Sterols in Foods • Found in plant and animal foods • Cholesterol is found in animal foods only—meat, eggs, fish, poultry and dairy products (exogenous).

50. The Chemist’s View of Phospholipids and Sterols • Sterols • Roles of Sterols • Starting material for bile acids, sex hormones, adrenal hormones and vitamin D • Structural component of cell membranes • Liver produces 800-1500 mg cholesterol per day (endogenous). • Atherosclerosis is a disease that causes heart attacks. It occurs when cholesterol forms deposits in the artery wall.