1 / 27

Chapter2 Lipids & Its Function

Chapter2 Lipids & Its Function. Professor, Dr. Jin Bangquan Department of Food Science & Nutrition NJNU. § 1 Concept. Lipids is as Fat Oil Lipid. 1 Neutral Fat

natara
Télécharger la présentation

Chapter2 Lipids & Its Function

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter2 Lipids & Its Function Professor, Dr. Jin Bangquan Department of Food Science & Nutrition NJNU

  2. §1 Concept Lipids is as Fat Oil Lipid

  3. 1 Neutral Fat Glycerin + Fatty Acids (FA) 1.1 Triglyceride, Diglyceride, Olyglyceride 1.2 C-chain of FA: short, Middle, Longer

  4. Neutral fat in food Triglyceride is by 95% Diglyceride + Olyglyceride is by 5% • Neutral fat in human body Triglyceride is by 99%

  5. 2 Lipids Containing: Phospholipids Glycolipids Sterols Lipoprotein P21-22

  6. 和动物组织含有的不饱和脂肪酸主要为软油酸(16:1△9)、油酸(18:1△9)、亚油酸(18:2△9,12)、亚麻酸(18:3△9,12,15)、花生四烯酸(20:4△5,8,11,14)等。其中最普通的单不饱和脂肪酸软油酸和油酸可由相应的脂肪酸活化后经去饱和酶(acylCoAdesaturase)催化脱氢生成（见下图）。这类酶存在于滑面内质网，属混合功能氧化酶；因该酶只催化在△9形成双键，而不能在C10与末端甲基之间形成双键，故亚油酸(linoleate)、亚麻酸(linolenate)及花生四烯酸(arachidonate)在体内不能合成或合成不足。但它们又是机体不可缺少的，所以必须由食物供给，因此，称之为必需脂肪酸(essential fatty acid)。 和动物组织含有的不饱和脂肪酸主要为软油酸(16:1△9)、油酸(18:1△9)、亚油酸(18:2△9,12)、亚麻酸(18:3△9,12,15)、花生四烯酸(20:4△5,8,11,14)等。其中最普通的单不饱和脂肪酸软油酸和油酸可由相应的脂肪酸活化后经去饱和酶(acylCoAdesaturase)催化脱氢生成（见下图）。这类酶存在于滑面内质网，属混合功能氧化酶；因该酶只催化在△9形成双键，而不能在C10与末端甲基之间形成双键，故亚油酸(linoleate)、亚麻酸(linolenate)及花生四烯酸(arachidonate)在体内不能合成或合成不足。但它们又是机体不可缺少的，所以必须由食物供给，因此，称之为必需脂肪酸(essential fatty acid)。 3 Fatty Acids (FA) 3.1 The C-chain length 3.1.1 Longer : > 14 C-chain 3.1.2 Middle: 8-12 C-chain 3.1.3 Shorter: < 6 C-chain 3.1.4 Free Fatty Acids (FFA) 3-5 C-chain P20-21

  7. 3.2 Saturation 3.2.1 Saturated Fatty Acid (FA) 3.2.2 Monounsaturated Fatty Acid (M-UFA) 3.2.3 Polyunsaturated Fatty Acid (PUFA)

  8. 3.3 FA Structure in Space 3.3.1 Cis-fatty Acid 3.3.2 Trans -fatty Acid

  9. 3.4 Essential fatty acid (EFA) Linoleate (18:2△) n-6,9 all cis√ Linolenate (18:3△) (α) n-3,6,9 all cis√ (γ )n-6,9,12 all cis Arachidonate (20:4 △) n- 6,9,12,15 all cis Others: 软油酸(16:1△9) 油酸(18:1△9) In Nutrition: n-3 & n-6 (or ω-3, ω-6) P21

  10. §2 Composition & Ratio in Body 1 Chemical: C、H、O (Mainly) N、S、P(Less) 2 Ratio:10-20% in body most in fatty tissue Lipids: 5% 3 Better Sources: Vegetable oil; eg: corn oil, sesame oil

  11. Fatty tissue

  12. 4 Analysis and its Equipment • Fat Extracter: Soxthem method • Instruments

  13. §3 CharacteristicsSuppl. 1Physical Chemical TendernessC-chain length Melting pointFA saturation FlavourFA location/Gly Notes: • Vegetable oil: Liquid status in the air temperature because it contains FA < 12C UFA mostly • Animal Fat: Solid status because it contains FA>14-20C mostly

  14. 2 ChemicalSuppl. • 氢化（Hydrogenation）: 双键打开以增加饱和度（人造奶油） • 乳化（Emulsification）:以水包油形式形成脂肪微粒（色拉） • 皂化（Saponification）:FA与阳离子形成不溶性物质 • 酸败（Rancidity）:FA氧化变质

  15. §4 Fatty FunctionP19 • Body Composition, Cell membrane structure • Padding (填充) Maintaining temperature • Insulation (绝缘) Protecting • Supplying Energy Coefficient = 9kcal/g 37.7kJ/g • Endo-secretive • Delaying empty in stomach, Increasing satiety • Improving palatability of foods • Carriers of fatty soluble vitamins, hormones

  16. Classification Stored Fat Variable Fat White Fat Brown Fat Suppl.

  17. Fatty tissue

  18. EFA Function • Phospholipids of ingredients • Prostaglandins (前列腺素) synthesisy from linolic acid • Taking part in cholesterolmetabolism • EFAwith vitamins deficiency Suppl.

  19. §5 Phospholipids & Steroids • Phospholipids: Kinds, Emulsifying agent • Steroids: Cholesterol: Testosterone, Cortisol, Vit. D P21-22

  20. §6Digestion, Absorption & Metabolism Upper small intestine Blood lymph Liver

  21. Transition types 4 kinds of Carried-lipo-protein • Chylomicron, CM 转运脂肪滴进中央乳管 • Very Low Density-, VLDL 肝中合成的脂肪 • Low Density-, LDL 转运并沉积其它 • High Density-, HDL 脂肪转运至肝中降解 Metabolic route: -氧化途径

  22. §7 Nutritional Evaluation Similar to protein 1 Fatty Digestivity: 90-98% 2EFA Content: oil > fat 3Vit. A, D, E Content

  23. §8 Lipids Sources and Supplement 1Sources: Vegetable & animal food 2RDA：50-70g/d/per； 3SupplyRatio：20-30%for adults 40-45% for infants • EFA in energy：3% Infants need more than above • Saturated FA: < 10% in intake • Cholesterolintake < 300mg/d/p (Committee on Diet and Health in US)

  24. Nowadays 油脂消费量 脂代谢疾病 北京/上海 83-85g/d 肥胖 高血脂 脂肪肝 冠心病

  25. Malnutrition • EFA deficiency • TG • Cholesterol P21-22

  26. Measuring Body Fat • Skinfold • Body Fat (%) • Broca (WB) = BH (cm)-100 • BMI = BW(kg)/ BH(m)2

  27. Quanstion 1脂肪的营养学意义？ 2 什么是类脂，包括哪些？ 3 必需脂肪酸？ 4 多不饱和脂肪酸，重要的有几种？ 5 何为载脂蛋白，它们的功能？ 6 摄入的脂肪应该包括哪些？ 7 日常生活中脂肪摄入过多，仅因为是动物食品过多吗？ 8 高脂饮食的危险性？ 9 近年中国人烹饪方式会引起脂肪摄入过高吗？ 10 动植物油脂的差异在哪？

More Related