营养学演示文稿1

NutritionandFoodHygiene营养与食品卫生教研室谢林营养与食品卫生学Conception:Thesciencewhichstudiesontherelationshipbetweenfoodnutritionandbodyhealth.Macronutrient:carbohydratesfatsproteinsMicronutrient:vitaminsmineralswater

Protein1.Physiologicalfunctions(1)Tobuilduphumanbody(2)Tocomposeavarietyofsubstanceswithimportantfunctions(3)Totransportothersubstance(4)Sourceofenergy2Aminoacids(1)EAAThr（苏氨酸）Met（蛋氨酸）Try（色氨酸）Phe（苯丙氨酸）Leu（亮氨酸）Ile（异亮氨酸）Lys（赖氨酸）Val（缬氨酸）His（组氨酸）Semi-essentialaminoacidCys（半胱氨酸）Tyr(酪氨酸）⑵AminoacidpatternandLAAEAApatternreferstothecomponentratioofvariousEAAintheprotein.LAAEAApresentinlowestamountrelativetotherequirementfortheproteinsynthesis.ComplementaryeffectsofproteinanyrelativedeficitofEAAinoneproteinfoodcanbecompensatedbyarelativesurplusinanother.3Nitrogenbalance(NB)dynamic动态的urine尿feces粪equilibrium平衡starvation饥饿trauma外伤，损伤adolescent青少年restoration恢复obligatory必需的equivalent相等的

4.Assessmentofthenutritionalvalueofprotein(1)ContentofproteinKjeldahlreaction凯氏定氮法(1)digestionprotein

(NH4)2SO4(2)distillation(NH4)2SO4

NH3(3)titrationNH4+NH4Clmultiplythecontentofnitrogenby6.25assessment评估nitrogen氮multiply乘conversion转换nucleicacid核酸phospholipids磷脂soybean大豆

Proteincontentofdairyfoodscereals:8g/100gsoybean:35-40g/100gmeats:15-20g/100gfishandegg:10-12g/100gfruitandvegetables:1-2g/100g⑵digestibility(D)(蛋白质消化率)Distheproportionofthedietaryproteinthatisabsorbedinthebody.ApparentD(%)=AbsorbedNIntakedN=(I–F)ITrueD(%)={I-(F-Fm)}/I×100I:intakenitrogenF:fecesnitrogen

Fm:fecalmetabolismnitrogen粪代谢氮formula公式intestine肠道bacteria细菌mucosa粘膜intake摄入absorb吸收×100×100⑶Biologicalvalue(BV)（蛋白质生物学价值）BV=retainedNabsorbedN=I-(F-Fm)-(U-Ue)I-(F-Fm)×100×100retain储留absorb吸收Ue(endogenousurineN)尿内源性氮I:intakenitrogenF:fecesnitrogenU:urinenitrogenFm:fecalmetabolismnitrogen⑷Netproteinutilization(NPU)（蛋白质净利用率）NPUistheproportionofthedietaryproteinthatisretainedinthebodyforproteinsynthesis.NPU=retainedN/intakedN×100％=BV×Dnet净余的

⑸Proteinefficiencyratio(PER)（蛋白质功效比值）PERisdefinedasthegaininweightpergmofproteineaten.PER=thegaininweightof