酶法制取甜柿果汁及其褐變控制.pdf

1、湖北工業(yè)大學碩士學位論文酶法制取甜柿果汁及其褐變控制姓名：萬楚筠申請學位級別：碩士專業(yè)：食品科學指導教師：周堅20050501湖北工業(yè)大學碩士學位論文AbstractThenonastringentpersimmonisaspecialpersimmonAllastringencycanberemovednaturallyfromnon—astringentpersimmonwhenitisstillonthepersimmontree

2、ThepickedpersimmoncanbeeatendirectlyafterhuskingwhichisverydeliciousandnoastringentfeelingThepersimmonhasnutritioninabundance，suchasVb5，Vbl，Vb2，VE，VCBCarotene，F(xiàn)e，Zn，andSeetcFurthermore，itcanbeusedasmedicine，Howevertheper

3、simmonwasmadesimplyintoasingleproduct，whichwasoftendriedpersimmon，foralongtimeSothenutritionvalueofthepersimmonhasalowerratioofutilizationAccordingtowhatismentionedabove，thisthesisstudiesthemanufacturetechnologyofnon—ast

4、ringentpersimmonjuicewithenzymatichydrolysis，flavoradjustingandstabilityofthejuiceAtthesametime，weinvestigatedthebrowningcontrol‘methodinprocessofthepersimmonjuiceproductionanditsrheologyThejuiceiseasytobrowning，whichisc

5、atalyzedbyPolyphenolOxidase(PPO)，inprocessingThereforethecharacteristicofPPOwasstudiedatfirstThePPOwasextractedfromthepersimmonfleshbywayofproducingtheacetonepowderWithcatecholassubstrate，theoptimumtemperaturewas20℃，theo

6、ptimumpHwas66and59，thevalueofKmwas9617mm01／LBaseonthetheoreticstudyofPPO，MicrowaveblanchingandcolorprotectingadditivewereusedtogethertoreducethebrowningdegreeofthepersimmonjuiceinprocessingThroughtheorthogonalexperiment，

7、theoptimumconditionswereobtainedasfollows：timeofmicrowaveblanching80s，thepower480WtheconcentrationofVc008％andtheconcentrationofcitricacidO1％Onthisconditions，browningratioofobtainedpersimmonjuicewasonly3127％Comparedwithth

8、etwoexperiments，aconclusioncouldbemadethatpectinasesandcellulaseshadthesynergeticeffectforliquefyingthepersimmonfleshUsingtheenzymatichydrolysistechnologyformanufacturingthepersimmonjuice，theoptimumconditionswere：dosageo

9、fcellulases6500U／2009Flesh，dosageofpectinases2500U／2009Flesh，enzymatictemperature45(2andenzymatictime25hThejuiceyieldwas79％。Onthisconditions，theobtainedjuiceyieldwas79％aThemixedsteadyadditiveandhighpressurehomogenizingwe