现代食品化学研究进展 4脂 质-2.ppt

BHA 脂溶性、耐热、遇Mn+不着色、能抗微生物；有酚的气味，BHA有一定的毒性。 BHT 无BHA那种异味，价廉，抗氧化能力强。 PG 抗氧化性能优于BHT和BHA；但口感不好，遇金属离子着色。 D-异抗坏血酸及其钠盐 1. Lecithin （卵磷脂） Phospholipids(磷脂): include glycerol phospholipids and non-glycerol phospholipids Lecithin → glycerol phospholipids Complex Lipids and Derivative Lipids   Structure of Lecithin Structure of Phospholipids R1为饱和脂肪酸， R2为不饱和脂肪酸 R3= -H为磷脂酸 (phosphatidic acid,PA) R3= -CH2CH2N+(CH3)3 为磷脂酰胆碱 (phosphatidyl choline, PC) R3= - CH2CH2NH2 为磷脂酰乙醇胺 (phosphatidyl ethanolamine, PE ) 为磷脂酰肌醇 (phosphatidyl inositol, PI) O H O H O H O H H O Phospholipid R3= Lecithin’s function ? 构成生物膜的成分 ? 参与脂肪的代谢 ? 健脑、增强记忆力 ? 乳化剂 ? 抗氧化剂 2. Cholesterol（胆固醇） 植物固醇：如麦角固醇、豆固醇、谷固醇 动物固醇： 胆固醇 an organic chemical substance classified as a waxy steroid of fat. It is an essential structural component of mammalian cell membranes. Cholesterol function Cholesterol is required to build and maintain membranes; Within the cell membrane, cholesterol also functions in intracellular transport, cell signaling and nerve conduction; Within cells, cholesterol is the precursor molecule in several biochemical pathways. too much cholesterol can clog arteries and lead to heart disease. Fat substitute a food product with the same functions, stability, physical, and chemical characteristics as regular fat, with fewer kilocalories per gram than fat. They are utilized in the production of low fat and low calorie foods. Category Type and example Function Carbohydrate-based Cellulose (Avicel) Dextrins, modified starches (Stellar) Fruit-based fibre (WonderSlim) Grain-based fibre (Betatrim) Hydrocolloid gums (Kelgum) Maltodextrin (Maltrin) Pectin (Grinsted) Binder, body, bulk, flavor, moisture retention, mouth feel Protein-based Microparticulate protein Modified whey protein concentrate (Dairy-Lo) Mouth feel, water-binding, reduce syneresis Fat-based Altered triglycerides (Caprenin) Sucrose polyester