生物微量元素研究—生物利用性与生物强化a ppt课件.ppt

1生物微量元素研究—生物利用性与生物强化Bioavailability and Biofortification of Trace Elements (TEs)学术沙龙报告之三主讲:胡广林(应化系)2012-11-29 2Topics to CoverIntroduction to Biological Trace Elements12Models to Evaluate Trace Elements Bioavailability3Biofortification of Trace Elements3Trace Elements?Definitions?Macroelements VS. Microelements? Macronutrients VS. Micronutrients?Absorption of Trace Elements?Functions & Deficiencies of Trace Elements?Iron (Fe), Zinc (Zn), Iodine (I), Selenium (Se)?Why Do Trace Elements Deficiencies Occur?4Definitions?Marcoelements?Include calcium (Ca), phosphorus (P), magnesium (Mg), sodium (Na), potassium (K) and chloride (Cl), etc.? Macroelements are required in amounts greater than 100 mg/?Microelements?Include iron (Fe), zinc (Zn), copper (Cu), selenium (Se), fluorine (F), iodine (I), ? Required in small quantities and are also known as ‘trace elements’6?Macronutrients include:Macronutrients VS. Micronutrients?Protein?Lipids?Carbohydrates7Macronutrients VS. Micronutrients?Micronutrients include:macromicro?Minerals?Vitaminsfat soluble (Vitamin A,D)water soluble (Vitamin B, C)维持人体的正常生理代谢,摄入不足会导致严重的疾病,甚至造成死亡!8Absorption of TEs?Digestion/absorption?吸收:胃肠道,呼吸道,也可以是皮肤9Absorption of TEs?Excretion?主要通过消化道(粪便)、肾脏(尿),呼吸、汗液也可排出少量10Absorption of TEs?pH affects absorption of TEs? Some minerals (Ca, Fe, Zn, Cu) are present in foods as insoluble salts.? Minerals from foods are solubilized in the stomach due to the acidity (HCl).? This solubility does not last long, since the intestine is more alkaline (pH ~7).