Megazyme/Protazyme OL Tablets/TPROL200T/200 Tablets

Dietaryfiberismainlycomposedofplantcellwallpolysaccharidessuchascellulose,hemicellulose,andpecticsubstances,butitalsoincludesligninandotherminorcomponents(1).Basically,itcoversthepolysaccharidesthatarenothydrolyzedbytheendogenoussecretionsofthehumandigestivetract(2,3).Thisdefinitionhasservedasthetargetforthosedevelopinganalyticalproceduresforthemeasurementofdietaryfiberforqualitycontrolandregulatoryconsiderations(4).Mostproceduresforthemeasurementoftotaldietaryfiber(TDF),orspecificpolysaccharidecomponents,eitherinvolvesomeenzymetreatmentstepsoraremainlyenzyme-based.InthedevelopmentofTDFproceduressuchastheProskymethod(AOACInternational985.29,AACC32—05)(5),theUppsalamethod(AACC32-25)(6),andtheEnglystmethod(7),theaimwastoremovestarchandproteinthroughenzymetreatment,andtomeasuretheresidueasdietaryfiber(afterallowingforresidual,undigestedproteinandash).Dietaryfiberwasmeasuredeithergravimetricallyorbychemicalorinstrumentalprocedures.Manyoftheenzymetreatmentstepsineachofthemethods,particularlytheprosky(5)andtheUppsala(6)methodsareverysimilar.Asanewrangeofcarbohydratesisbeingintroducedaspotentialdietaryfibercomponents,theoriginalassayprocedureswillneedtobereexamined,andinsomecasesslightlymodified,toensureaccurateandquantitativemeasurementofthesecomponentsandofTDF.These“new”dietaryfibercomponentsincluderesistantnondigestibleoligosaccharides;nativeandchemicallymodifiedpolysaccharidesofplantandalgalorigin(galactomannan,chemicallymodifiedcelluloses,andagarsandcarrageenans);andresistantstarch.Tomeasurethesecomponentsaccurately,thepurity,activity,andspecificityoftheenzymesemployedwillbecomemuchmoreimportant.Aparticularexampleofthisisthemesurementoffructan.Thiscarbohydrateconsistsofafractionwithahighdegreeofpolymerization(DP)thatisprecipitatedinthestandardProskymethod(5,8)andalowDPfractionconsequentlyisnotmeasured(9).Resistantstarchposesaparticularproblem.Thiscomponentisonlypartiallyresistanttodegradationbyα-amylase,sothelevelofenzymeusedandtheincubationconditions(timeandtemperature)arecritical.

Linenistheyarnorthefabricsmadefromfibresoftheflaxplant(Linumusitatissumum),which,likeotherbastfibrecrops,canbegrowninmoderateclimatesandneedslowinputofagrochemicalstogivehighyields.Beforecottontookoverasthemainplant-derivedtextilematerial,linenwasoneofthemostimportantsourceoftextilefibres.Followingafewdecadesofalmostabandonment,flaxfibresarebeingre-evaluatedthankstotheuniquefeaturesoffreshness,comfortandeleganceoflinenapparels,sheets,towelsandotherhouseholdtextileitems.However,flaxprocessingintoyarnessentiallystillfollowstraditionalmethodologies.Wehavereinvestigatedtheeffectsofseveralwellcharacterized,mostlyrecombinant,industrialenzymesonrawflaxrove(onapilotscalefromfourtimes1kgspoolsupto130kgofmaterial)asanalternativetochemicalscouring,followedbyasinglebleachingstepandbyyarnwetmechanicalspinning.Afterspinning,allrelevantyarnparametersweremeasuredandevaluated(e.g.,resistance,stretching,percentageofneps,etc.).Inthepresentwork,wedemonstratetheadvantagesofscouringwiththeenzymestested,usedundermildreactionconditions,incomparisonwithtraditionalchemicalscouring.Thedecreasingorderofeffectivenesswas:pectinase>xylanase=galactomannanase=protease>lipase>or=laccase.Asimpleandstraightforwardschemeofrovebiopreparationandbleachingisproposed,followedbywetspinningtoyieldahighqualitylinenyarn.

Activepackaging,inwhichactiveagentsareembeddedintooronthesurfaceoffoodpackagingmaterials,canenhancethenutritivevalue,economics,andstabilityoffood,aswellasenablein-packageprocessing.Inoneembodimentofactivefoodpackaging,lactasewascovalentlyimmobilizedontopackagingfilmsforin-packagelactosehydrolysis.Inpriorwork,lactasewascovalentlyboundtolow-densitypolyethyleneusingpolyethyleneimineandglutaraldehydecross-linkerstoformthepackagingfilm.Becauseofthepotentialcontaminantsofproteases,lipases,andspoilageorganismsintypicalenzymepreparations,thegoalofthecurrentworkwastodeterminetheeffectofimmobilized-lactaseactivepackagingtechnologyonunanticipatedsideeffects,suchasshortenedshelf-lifeandreducedproductquality.Resultssuggestednoevidenceoflipaseorproteaseactivityontheactivepackagingfilms,indicatingthatsuchactivepackagingfilmscouldenablein-packagelactosehydrolysiswithoutadverselyaffectingproductqualityintermsofdairyproteinorlipidstability.Storagestabilitystudiesindicatedthatlactasedidnotmigratefromthefilmovera49-dperiod,andthatdrystorageresultedin13.41%retainedactivity,whereaswetstorageconditionsenabledretentionof62.52%activity.Resultsofastandardplatecountindicatedthatthefilmmodificationreagentsintroducedminormicrobialcontamination;however,themicrobialpopulationremainedunderthe20,000cfu/mLlimitthroughthemanufacturer’ssuggested14-dstorageperiodforallfilmsamples.Thissuggeststhatcommerciallyproducedimmobilizedlactaseactivepackagingshouldusepurifiedcross-linkersandenzymes.Characterizationofunanticipatedeffectsofactivepackagingonfoodqualityreportedhereisimportantindemonstratingthecommercialpotentialofsuchtechnologies.

Background:Glutamicpeptidases,fromtheMEROPSfamilyG1,areadistinctgroupofpeptidasescharacterizedbyacatalyticdyadconsistingofaglutamateandaglutamineresidue,optimalactivityatacidicpHandinsensitivitytowardsthemicrobialderivedproteaseinhibitor,pepstatin.Previously,onlyglutamicpeptidasesderivedfromfilamentousfungihavebeencharacterized.Results:Wereportthefirstcharacterizationofabacterialglutamicpeptidase(pepG1),derivedfromthethermoacidophilicbacteriaAlicyclobacillussp.DSM15716.TheaminoacidsequenceidentitybetweenpepG1andknownfungalglutamicpeptidasesisonly24-30%buthomologymodeling,thepresenceoftheglutamate/glutaminecatalyticdyadandanumberofhighlyconservedmotifsstronglysupporttheinclusionofpepG1asaglutamicpeptidase.PhylogeneticanalysisplacespepG1andotherputativebacterialandarchaealglutamicpeptidasesinaclusterseparatefromthefungalglutamicpeptidases,indicatingadivergentandindependentevolutionofbacterialandfungalglutamicpeptidases.PurificationofpepG1,heterologouslyexpressedinBacillussubtilis,wasperformedusinghydrophobicinteractionchromatographyandionexchangechromatography.Thepurifiedpeptidasewascharacterizedwithrespecttoitsphysicalproperties.TemperatureandpHoptimumswerefoundtobe60°CandpH3-4,inagreementwiththevaluesobservedforthefungalmembersoffamilyG1.Inaddition,pepG1wasfoundtobepepstatin-insensitive,acharacteristicsignatureofglutamicpeptidases.Conclusions:Basedontheobtainedresults,wesuggestthatpepG1canbeaddedtotheMEROPSfamilyG1asthefirstcharacterizedbacterialmember.

Theaimoftheworkwastoelucidatetheimpactsoftreatmentwithxylanaseathigh(90%)andlow(40%)watercontentsonthestructuralandphysicochemicalpropertiesofwheatbran.Thebrantreatmentsat40%watercontent,bothwithandwithoutaddedxylanase,resultedinasmalleraveragebranparticlesize,morechangesinbranmicrostructure,andhighersolubilizationofpolysaccharidesthanthecorrespondingtreatmentsat90%.Also,thewaterholdingcapacityofbran(3.6 ± 0.1gwater/gbrandm),determinedbyBaumannmethod,decreasedmorealreadyafter4-hxylanasetreatmentsat40%(2.4 ± 0.1)thanat90%(2.9 ± 0.2).Thesolubilityofsalt-extractablebranproteinsdecreasedduringthetreatments,especiallyat40%,alsowithoutaddedxylanase.ProteinaggregationwasdetectedintheSDS + DTT-extractablebranfraction,whichalsocontainedsmallproteinsof10–20kDanotdetectableintheuntreatedbran.Theuseofxylanasehadonlyminoreffectonbranproteinsascomparedtothetreatmentswithoutaddedxylanase.Theresultsindicatethelargeroleofmechanicalshearonthebranpropertiesat40%watercontent.Thelowarabinose/xyloseratio(0.32)inthebranwaterextractafter24-hxylanasetreatmentat40%,however,suggeststhatthesolubilizationofarabinoxylanwascausedbyenzymaticaction,andnotbymechanicaldegradation.Arabinose/xyloseratioofthebranwaterextractdecreasedsimilarlyduringallthetreatments,suggestingsimilarsolubilizationpatternofarabinoxylanatbothwatercontents.Thestudyshowedthatbranpropertiescanbesignificantlymodifiedbyadjustingthewatercontentandmechanicalenergyusedinprocessing.