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Topics for Today

Topics for Today. What is a trans fat?. Readings For Today (Review). 11.3 Fat & Oils: Part of the lipid family 11.4 Saturated and Unsaturated Fats & Oils. Topics for Friday. “Acid” Rain Quiz 10. Topics. pH and acid rain Effects of acid rain SO 2 and NO x revisited.

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Topics for Today

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  1. Topics for Today • What is a trans fat?

  2. Readings For Today (Review) • 11.3 Fat & Oils: Part of the lipid family • 11.4 Saturated and Unsaturated Fats & Oils

  3. Topics for Friday • “Acid” Rain • Quiz 10

  4. Topics • pH and acid rain • Effects of acid rain • SO2 and NOx revisited

  5. Readings for Friday • 6.4 Introducing pH • 6.5 Measuring the pH of rain • 6.6 In search of the extra acidity

  6. Readings for Friday • 6.7 Sulfur dioxide (review) • 6.8 Nitrogen oxides (review) • 6.9 SOx and NOx • 6.10 Acid deposition and its effects on materials

  7. Announcements! Please have to me by Friday! Exam #3 regrades

  8. Announcements! Exam 4 next Friday (May 4)!! Optional!

  9. Topics for Today • What is a trans fat?

  10. Topics for Today • What is a trans fat? What is a fat?

  11. A triple ester! Three Triple H+ Fatty Acids + Alcohol Triglyceride + Water Fats Oils

  12. Figure 11.8 (p. 497) Figure 11.8 (p. 497)

  13. Figure 11.8 (p. 497) Figure 11.8 (p. 497)

  14. Butter Very high level of saturation! 29% Palmitic Acid 9% Stearic Acid 31% Other Saturated About 69% saturated fat!

  15. In general… • Saturated fats = Solid (Crisco, lard) WHY?

  16. Saturated fatty acids pack better!

  17. In general… • Saturated fats = Solid (Crisco, lard) • Animals usually have more saturated fatty acids than plants • Unsaturated fats = liquids

  18. Whale blubber 10-20% palmitic acid 2-5% stearic acid 5-10% other fatty acids ~ 25% saturated fatty acids Medium level of saturation

  19. Speaking of whales…

  20. What do you do with a dead 8 ton, 45 foot whale that beached itself? In 1970…

  21. Video! • http://whale.wheelock.edu/movies “The infamous exploding whale.”

  22. “’It went just exactly right,’ Thornton said. Except the blast funneled a hole in the sand under the whale.” “Where the whale had been, there was a large hole”

  23. A small boy ran down the beach ahead of his father. “Look,” the boy cried. “A piece of the whale.”

  24. After the large pieces had fallen, it began to rain small particles of foul-smelling blubber. Many in the crowd ran for their cars and drove away. But they wouldn’t be rid of the nauseating odor until they bathed and washed their clothes and cars. Where did the odor come from?

  25. 1) Amines! Putrescine Cadaverine Products from the breakdown of amino acids

  26. 2) Rancid fats! Oxidation of fatty acid chains…

  27. Oxygen, O2 Reacts with fatty acids WHY? Mainly the unsaturated ones A colorless, odorless, tasteless gas

  28. Fats going rancid Double Bond = Reactive!

  29. Creates two smaller carboxylic acids!! Oxygen and ROS will help “split” the fatty acid at the double bond

  30. Carboxylic Acids!! • Propanoic Acid (Propionic Acid) • CH3CH2COOH O CH3 CH2 C OH Limburger cheese smell…

  31. Butanoic Acid (Butyric Acid) Rancid Butter O CH3 CH2 CH2 C OH

  32. Butyric Acid Locker Room Smell O CH3 CH2 CH2 C OH

  33. Unsaturated fats go rancid quicker than saturated. Reactive!!

  34. How do we remove the double bond? The same goes for the products in our kitchen!

  35. Hydrogenation – The process of adding hydrogen to a double bond. Creates a saturated molecule from an unsaturated one!

  36. Hydrogenation – The process of adding hydrogen to a double bond. Creates a saturated molecule from an unsaturated one!

  37. Review! Same as with crude oil!

  38. Hydrogenation of ethylene H H H H catalyst H2 + C = C C C H H H H H H Ethene Ethane

  39. Hydrogenation of propylene H H H CH3 H catalyst H2 + C C = C C C H H H H H H H Propene Propane

  40. Hydrogenation of a fatty acid Complete hydrogenation! O C OH catalyst H2 + C = C H H H H O C C C OH H H

  41. (Oleic Acid) catalyst H2 + (Stearic Acid)

  42. Hydrogenation H2 + unsaturated fatty acid  saturated fatty acid (usually oil) (usually fat)

  43. Why hydrogenate foods?

  44. Butanoic Acid (Butyric Acid) 1) Longer shelf-life! O CH3 CH2 CH2 C OH

  45. Margarine contains “partially hydrogenated soybean oil.” 2) More spreadable!

  46. NOT Hydrogenated Hydrogenated

  47. Peanut Oil! NOT Hydrogenated Hydrogenated

  48. NOT Hydrogenated Hydrogenated More unsaturated fat (healthier)

  49. Hydrogenation Why make the food less healthy? H2 + unsaturated fatty acid  saturated fatty acid (usually oil) “Good” Fats (usually fat) “Bad” Fats

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