第6章 维生素与矿物质.ppt

第6章维生素与矿物质 (Vitamin and Minerals)
制作人: 李春美
Introduction of Vitamins
辅酶或辅酶前体:如烟酸,叶酸等
维生素的功能抗氧化剂:VE,VC
遗传调节因子:VA,VD
某些特殊功能:VA-视觉功能
VC-血管脆性
Learning Objectives –Vitamins
Describe the structure and stability of vitamins.
Describe the functions of vitamins.
Identify food and nonfood sources of vitamins.
Describe the signs and symptoms of vitamin deficiencies and toxicities.
Learning Objectives – cont.
Identify the population group or groups at risk for vitamin and mineral deficiencies.
Compare your own intake of vitamins to the ideal and identify any potential health risks associated with your intake.
VB1,VB2,VPP
B族 VB5,VB6,VH
water-soluble Vit VB11,VB12
Vit VC
VA
fat-souble Vit VD
VE
VK
Classification of Vit
The Water-solubke vitamin
Overview of Water-Soluble Vitamins
Dissolve in water
Generally readily excreted
Subject to cooking losses
Function as a coenzyme
Participate in energy metabolism
50-90% of B vitamins are absorbed
Marginal deficiency mon
一 BVit- VB1 (thiamin)
Contains sulfur and nitrogen group
Destroyed by alkaline and heat
Coenzyme: Thiamin pyrophosphate (TPP)
①具有酸-碱性质
②对热非常敏感,在碱性介质中加热易分解.
③能被VB1酶降解,同时,血红蛋白和肌红蛋白可作为降解的非酶催化剂.
④对光不敏感,在酸性条件下稳定,在碱性及中型介质中不稳定.
⑤其降解受AW影响极大,-.
Stability and Properties
硫胺素和脱羧辅酶降解速率与pH的关系