9,Shelf-life of fresh noodles as affected by chitosan and its

壳聚糖

LWT40(2007)1287–1291

doc.guandang.net

Shelf-lifeoffreshnoodlesasaffectedbychitosanandits

Maillardreactionproducts

Jin-ruHuanga,Chung-yiHuanga,Yao-wenHuangb,Ã,Rong-huiChenc

b

DepartmentofFoodScience,NationalI-LanUniversity,I-Lan,Taiwan,ROC

DepartmentofFoodScienceandTechnology,UniversityofGeorgia,Athens,GA30602,USAc

DepartmentofFoodScience,NationalTaiwanOceanUniversity,Keelung,Taiwan,ROC

a

Received4November2005;receivedinrevisedform4August2006;accepted8August2006

Abstract

TheeffectsofMaillardreactionproducts(MRPs)preparedfromchitosanandxyloseontheshelf-lifeoffreshnoodleswerestudied.Amodelsystemconsistingofchitosanandxylose(1:1.5,w/w)dispersedindistilledwaterwithpHvaluesof5,6,7,9wasused.Thesystemswereheatedto951Cforupto60h.ThedevelopmentofbrowncolorwasmorepronouncedinthemodelsystemwithahigherinitialpHofthewater.TheantibacterialactivityofchitosanincreasedatthebeginningoftheMaillardreaction,andtheminimuminhibitionconcentration(MIC)ofchitosanagainstBacillussubtilisCCRC10258decreasedto50mg/mlofmediumfrom250mgasaresultoftheMaillardreaction.Gram-positivebacteriaweremoresensitivetochitosanoritsMRPsthanGram-negativebacteria.MRPofchitosan/xyloseshowedabactericidaleffectagainstBacillussubtilisCCRC10258,whilechitosanshowedabacteriostaticeffectpriortotheoccurrenceoftheMaillardreaction.Additionof0.05g/100mlchitosan(in0.5ml/100mlaceticacid)tofreshnoodleformulationresultedinanextensionofitsshelf-lifefor6moredayswhenstoredat41C.However,additionofMRPresultedinthelongershelf-lifelasting14dayswhenstoredat41C.

r2006SwissSocietyofFoodScienceandTechnology.PublishedbyElsevierLtd.Allrightsreserved.

Keywords:Chitosan;Xylose;Maillardreactionproduct(MRP);Shelf-life;Bacteriostatic;Preservative;Freshnoodle

1.Introduction

Chitosanisalinearpolyamine(Tanaka,Huang,Chiu,Shoichiro,&Takeshi,1993)andanaturalnontoxicbiopolymer(Hong,Na,Shin,&Lsamuel,2002)derivedbythealkalinedeacetylationofchitin,amajorcomponentoftheshellsofcrustacean,suchasshrimp,craw shandcrab.Mostofthecommercialhighmolecularweighthydrocolloidsorpolysaccharidesusedinindustriesareneutralorpolyanionic.Chitosan,acationicpolyelectro-lyte,isoneoffewexceptions.Theuniquephysical,chemical,andbiologicalpropertiesofthepositivelychargedchitosaninacidicsolutionmayhaveanenormouspotentialincosmetic,medical,andfood-relatedindustries.Inpharmaceutical elds,chitosanhasbeenusedasanantimicrobialagentaswellasanencapsulationsubstance

Correspondingauthor.Tel.:+7065421092;fax:+7065421050.

E-mailaddress:huang@uga.edu(Y.-w.Huang).

fordrugingredients(ElGhaouth,Grenier,&Asselin,1992;Vorlop&Klein,1981).Chitosanhavebeenstudiedfortheapplicationontreatmentofcheddarcheesewhey(Savant&Torres,2000)andsurimiwashwater(Wibowo,Torres,Savant,&VelazquezdelaCruz,2004).Arecentstudydemonstratedthatthecomplexprocessinvolvedindeterminingtheantimicrobialactivityofchitosanonrawoystersduetotheeffectsofchitosandifferdependingonthespeciesofmicrobialcontaminant(Chhabra,Huang,Frank,&Gates,2006).

TheMaillardreaction,alsocalledthenonenzymaticbrowningreaction,isareactionbetweenaminogroupsandreducingcompounds.Infoodsystems,theaminocom-poundsaremostlyfreeorprotein-boundaminoacidswhilethereducingsugarsareoneofthemostcommonlyprevalentchemicalcompoundsthatexistduringfoodprocessingandpreservation.Therefore,therehasbeenagrowinginterestinthephysiologicalaspectsoftheMaillardreactioninfoodandbiologicalsystems.Most

0023-6438/$30.00r2006SwissSocietyofFoodScienceandTechnology.PublishedbyElsevierLtd.Allrightsreserved.doi:10.1016/j.lwt.2006.08.004