1. © 2006 Thomson-Wadsworth The Lipids Triglycerides Phospholipids Sterols

2. © 2006 Thomson-Wadsworth Lipids Triglycerides –Fats and oils Phospholipids Sterols

3. © 2006 Thomson-Wadsworth Fatty Acids and Triglycerides glycerol

4. © 2006 Thomson-Wadsworth Fatty Acids and Triglycerides glycerol + 3 fatty acids  triglyceride + H 2 O

5. © 2006 Thomson-Wadsworth

6. Fatty Acids Fatty acids –Length –Saturated vs. unsaturated

7. © 2006 Thomson-Wadsworth Fatty Acids Organic acids –Example: acetic acid

8. © 2006 Thomson-Wadsworth Fatty Acids Length of carbon chain Stearic acid – 18-carbon, saturated Simplified structure

9. © 2006 Thomson-Wadsworth Fatty Acids Point of saturation Degree of saturation –Saturated fatty acid –Monounsaturated fatty acid –Polyunsaturated fatty acid

10. © 2006 Thomson-Wadsworth An impossible chemical structure Oleic acid – 18-carbon, monounsaturated Linoleic acid – 18-carbon, polyunsaturated

11. © 2006 Thomson-Wadsworth Fatty Acids Location of double bonds –Omega number Omega-3 fatty acid Omega-6 fatty acid

12. © 2006 Thomson-Wadsworth

13. Triglycerides Degree of unsaturation revisited –Firmness –Stability Oxidation –Antioxidants

14. © 2006 Thomson-Wadsworth

15. Triglycerides Degree of unsaturation revisited –Hydrogenation –Cis vs. trans-fatty acids

16. © 2006 Thomson-Wadsworth

18. Phospholipids

19. © 2006 Thomson-Wadsworth Phospholipids Phospholipids in foods Roles of phospholipids –Plasma membrane –Emulsifiers

20. © 2006 Thomson-Wadsworth Phospholipids

21. © 2006 Thomson-Wadsworth Sterols

22. © 2006 Thomson-Wadsworth Sterols Sterols in foods

23. © 2006 Thomson-Wadsworth Sterols Roles of sterols –Bile acids –Sex hormones –Adrenal hormones –Vitamin D

24. © 2006 Thomson-Wadsworth Sterols Cholesterol and atherosclerosis

25. © 2006 Thomson-Wadsworth Lipids Hydrophobic vs. hydrophilic

26. © 2006 Thomson-Wadsworth Fat Digestion Hydrolysis –Triglycerides  monoglycerides, fatty acids, glycerol

27. © 2006 Thomson-Wadsworth Fat Digestion

28. © 2006 Thomson-Wadsworth Fat Digestion Mouth –Melting –Lingual lipase

29. © 2006 Thomson-Wadsworth Fat Digestion Stomach –Churning and mixing –Gastric lipase

30. © 2006 Thomson-Wadsworth Fat Digestion Small intestine –CCK Bile and emulsification

31. © 2006 Thomson-Wadsworth Fat Digestion

32. © 2006 Thomson-Wadsworth Fat Digestion

33. © 2006 Thomson-Wadsworth Fat Digestion Small intestine –Pancreatic lipases –Intestinal lipases

34. © 2006 Thomson-Wadsworth Fat Digestion Overview

35. © 2006 Thomson-Wadsworth Fat Digestion Enterohepatic circulation

36. © 2006 Thomson-Wadsworth Lipid Transport Lipoproteins –Chylomicrons –VLDL = very-low-density lipoproteins –LDL = low-density lipoproteins –HDL = high-density lipoproteins

37. © 2006 Thomson-Wadsworth Lipid Transport Lipoproteins and health –LDL vs. HDL

38. © 2006 Thomson-Wadsworth Roles of Triglycerides Fat stores –Energy –Protection –insulation

39. © 2006 Thomson-Wadsworth Essential Fatty Acids Linoleic acid and the omega-6 family –Arachidonic acid

40. © 2006 Thomson-Wadsworth Essential Fatty Acids

41. © 2006 Thomson-Wadsworth Essential Fatty Acids Linolenic acid and the omega-3 family –EPA =eicosapentaenoic acid –DHA = docosahexaenoic acid

42. © 2006 Thomson-Wadsworth Essential Fatty Acids Eicosanoids –EPA derived vs. arachidonic acid derived Fatty acid deficiencies

43. © 2006 Thomson-Wadsworth

44. Health Effects of Lipids Benefits from monounsaturated fats and polyunsaturated fats

45. © 2006 Thomson-Wadsworth Health Effects of Lipids Benefits from omega-3 fats Balance omega-6 and omega-3 intakes

46. © 2006 Thomson-Wadsworth Recommended Intakes of Fat DRI: 20% - 35% of energy intake

47. © 2006 Thomson-Wadsworth Recommended Intakes of Fat Linoleic acid AI –5% - 10% of energy intake Linolenic acid AI –0.6 - 1.2% of energy intake

48. © 2006 Thomson-Wadsworth Guidelines to Groceries Meats and meat alternatives

49. © 2006 Thomson-Wadsworth

50. Guidelines to Groceries Milk and milk products Vegetables, fruits, and grains Invisible fat

51. © 2006 Thomson-Wadsworth

52. Guidelines to Groceries Fat replacers –Artificial fats Olestra

53. © 2006 Thomson-Wadsworth High-Fat Foods Changing guidelines for fat intake

54. © 2006 Thomson-Wadsworth High-Fat Foods Cook with olive oil Nibble on nuts Feast on fish –But beware of mercury