第一章植物学基础2营养与食品卫生PPT.ppt

第一章 营养学基础;Main contents ;Carbohydrates are one of the three macronutrient types that provide energy to our bodies. Carbohydrates contain carbon, hydrogen, and oxygen. 碳水化合物：属三大能量营养素之一，主要由碳、氢、氧构成。;We obtained carbohydrates predominantly from plant foods such as fruits, vegetables, and grain. ;Plants make carbohydrates through the process of photosynthesis;HO;Monosaccharides-Glucose（葡萄糖）;Monosaccharides-Fructose（果糖）;Monosaccharides-Galactose（半乳糖）;Sweetest monosaccharides? The most abundant monosaccharides ?;Disaccharide（双糖）;Disaccharides– Lactose（乳糖）;Disaccharides—Maltose （麦芽糖）;Disaccharides—Sucrose（蔗糖）;哪种双糖最甜--麦芽糖，蔗糖，乳糖？;Oligosaccharide（寡糖）;Polysaccharides（多糖）;Polysaccharides;Polysaccharide--Starch; Our bodies easily digest most starches， we call them digestible starch(可吸收淀粉）. 根据其结构可分为直链淀粉（amylose）和支链淀粉（amylopectin），前者易使食物老化，后者易使食物糊化（gelatinization ）。;However, some starch in plants is not digestible and is called resistant starch（抗性淀粉）. 抗性淀粉：指健康者小肠中不吸收的淀粉及其降解产物。 ;When our intestinal bacteria try to digest resistant starch, a fatty acid called butyrate is produced. Consuming resistant starch may be beneficial because butyrate is suggested to reduce the risk of cancer.;Glycogen: A polysaccharide stored in animals, including humans. Very little glycogen exists in food. Thus, glycogen is not a dietary source of carbohydrate. ;Which tissues are abundant in glycogen?;Based on the water soluble ability, fiber can be classified into soluble fibers and insoluble fibers. Insoluble fibers（不溶性纤维）: cellulose（纤维素）, hemicellulose（半纤维素） and xylogen（木质素）. Soluble fibers（可溶性纤维）:果胶（pectin) ，树胶和粘胶. ;膳食纤维（dietary fiber）：是指植物性食物或原料中糖苷键大于3个，不能被人体小肠消化和吸收，但对人体健康有意义的碳水化合物。 膳食纤维包括部分非淀粉多糖（纤维素、半纤维素、木质素、果胶等）、抗性淀粉、葡聚糖以及部分低聚糖等。 ; (1)增强肠道功能、有利粪便排出 Helps prevent constipation and other intestinal problems by keeping our stools moist and soft.; (2) 控???体重和减肥 May enhance weight loss, as eating a high fiber diet causes a person to feel more full. ; (3) 降低血糖和血胆固醇 Decrease the level of blood