Saini

meatȱtenderizingȱagentȱandȱasȱaȱneutraceuticalȱ(Lotz-

flavourȱcompoundsȱandȱnutrients,ȱallowȱuseȱofȱlowȱ

Winterȱ1990).

molecularȱweightȱosmoticȱagentsȱe.g.ȱNaCl,ȱprovideȱ

Theȱ majorȱ limitationȱ ofȱ ODȱ isȱ theȱ penetrationȱ ofȱ

physicalȱstrengthȱtoȱfoodȱpiecesȱtoȱwithstandȱmixingȱ

largeȱamountȱofȱsoluteȱintoȱtheȱfoodȱmaterial,ȱwhichȱ

duringȱprocessingȱandȱminimizeȱoxidationȱactivityȱ

bringsȱ aboutȱ theȱ resistanceȱ forȱ massȱ exchangeȱ ofȱ

duringȱstorage.ȱTheȱmainȱobjectiveȱofȱthisȱstudyȱwasȱ

waterȱinȱfurtherȱdehydrationȱprocesses.ȱItȱmodifiesȱ

toȱdetermineȱtheȱeffectȱofȱpectinȱasȱaȱcoatingȱagentȱ

theȱfinalȱproductȱcompositionȱandȱtasteȱandȱresultsȱ

onȱtheȱmassȱtransferȱduringȱODȱofȱpineapplesȱwithȱ

inȱ theȱ developmentȱ ofȱ concentratedȱ solidsȱ layerȱ

differentȱconcentrationsȱofȱcoatingȱsolution,ȱtimeȱofȱ

underȱ theȱ productȱ surfaceȱ upsettingȱ theȱ osmoticȱ

dippingȱinȱcoatingȱsolutionȱandȱdryingȱtime.

pressureȱ gradientȱ acrossȱ theȱ product-mediumȱ

interfaceȱandȱdecreasingȱtheȱdrivingȱforceȱforȱflowȱofȱ

Materials and Methods

waterȱ(HawkesȱandȱFlinkȱ1978;ȱLazarides,ȱ2001).ȱToȱ Pineapplesȱ wereȱ procuredȱ fromȱ theȱ localȱ market,ȱ

overcomeȱtheȱproblemȱofȱsoluteȱintake,ȱapplicationȱ Sangrurȱ forȱ massȱ transferȱ studies.ȱ Sucroseȱ wasȱ

ofȱcoatingȱonȱtheȱfruitsȱcanȱbeȱintroducedȱpriorȱtoȱ usedȱ asȱ theȱ osmoticȱ agent.ȱ Pectinȱ (Siscoȱ Researchȱ

OD.ȱ Thisȱ willȱ efficientlyȱ hinderȱ theȱ penetrationȱ ofȱ

Laboratoriesȱ Privateȱ Limited,ȱ Mumbai)ȱ wasȱ usedȱ

soluteȱinsideȱtheȱfoodȱwithoutȱseriouslyȱaffectingȱtheȱ

asȱcoatingȱagent.ȱCalciumȱchlorideȱ(SiscoȱResearchȱ

rateȱofȱwaterȱremovalȱ(IshikawaȱandȱNaraȱ1993;ȱKhinȱ

LaboratoriesȱPrivateȱLimited,ȱMumbai)ȱwasȱusedȱasȱ

et al .ȱ2005;ȱLenartȱandȱDabrowskaȱ1999;ȱLewickiȱ et al .ȱ

aȱcrossȱlinkingȱagent.

1984;ȱSinghȱ et al .ȱ2011).

Edibleȱcoatingsȱareȱdefinedȱasȱthinȱlayersȱofȱedibleȱ

Coating Prior to Osmotic Dehydration

materialȱ appliedȱ onȱ theȱ foodsȱ byȱ immersing,ȱ Pineapplesȱ wereȱ peeledȱ andȱ cutȱ intoȱ cuboidsȱ ofȱ

sprayingȱ orȱ wrappingȱ toȱ offerȱ aȱ selectiveȱ barrierȱ sizeȱ 2.0x2.0x0.75ȱ cm 3 .ȱ Pectinȱ wasȱ selectedȱ asȱ aȱ

againstȱtransmissionȱofȱgases,ȱvapoursȱandȱsolutesȱ coatingȱagentȱbecauseȱofȱitsȱhighȱperformanceȱratioȱ

whileȱalsoȱofferingȱmechanicalȱprotection.ȱTheȱtermȱ demonstratedȱ inȱ theȱ screeningȱ experiments.ȱ Theȱ

coatingȱisȱusedȱwhenȱitȱisȱappliedȱdirectlyȱandȱformedȱ differentȱ concentrationsȱ ofȱ pectinȱ solutionsȱ wereȱ

onȱ theȱ surfaceȱ ofȱ theȱ productȱ whileȱ theȱ termȱ filmȱ preparedȱ(0.5%,ȱ1%,ȱ2%,ȱ3%,ȱ4%ȱandȱ5%,ȱw/v)ȱwithȱ

isȱusedȱwhenȱitȱisȱformedȱseparatelyȱasȱthinȱsheetsȱ distilledȱwater.ȱTheȱpineappleȱsamplesȱwereȱweighedȱ

andȱappliedȱonȱtheȱproductsȱ(GennadiosȱandȱWellerȱ

andȱdippedȱintoȱtheȱsolutionȱofȱcoatingȱagentȱforȱtwoȱ

1990).ȱAqueousȱsolutionsȱofȱpotatoȱandȱcornstarches,ȱ

differentȱtimeȱofȱ60ȱsȱandȱ120ȱs.ȱPineappleȱsamplesȱ

gelatin,ȱ amylopectin,ȱ pectin,ȱ maltodextrin,ȱ wheatȱ

wereȱtakenȱoutȱfromȱtheȱcoatingȱsolution,ȱdrainedȱtoȱ

gluten,ȱsodiumȱalginate,ȱmethylcelluloseȱandȱchitosanȱ

removeȱadheringȱsolutionȱforȱ30ȱsȱandȱthenȱdippedȱ

areȱ usedȱ forȱ theȱ coatingȱ ofȱ fruitsȱ andȱ vegetablesȱ

intoȱCaCl ₂ ȱsolutionȱ(2%ȱw/v),ȱwhichȱwasȱusedȱasȱaȱ

cross-linkingȱ agent.ȱ Theȱ crossȱ linkingȱ timeȱ wasȱ 30ȱ

(Camirandȱ et al .ȱ1992;ȱLenartȱandȱDabrowskaȱ1997;ȱ

sȱforȱallȱtheȱcoatedȱsamples.ȱTheȱsamplesȱwereȱthenȱ

Lewickiȱ et al .ȱ1984;ȱWongȱ et al .ȱ1994).

takenȱoutȱfromȱtheȱCaCl ȱsolutionȱandȱdriedȱinȱaȱhot-

2

Theȱ edibleȱ coatingsȱ shouldȱ haveȱ theȱ followingȱ airȱovenȱatȱ50°Cȱtoȱfixȱtheȱlayerȱofȱcoatingȱforȱ10ȱandȱ

characteristicsȱ forȱ theȱ purposeȱ ofȱ osmoticȱ 40ȱminȱfollowedȱbyȱOD,ȱwhichȱwasȱcarriedȱoutȱatȱtheȱ

dehydrationȱ (OSMEMB)ȱ process:ȱ goodȱ mechanicalȱ optimizedȱODȱconditionsȱasȱdescribedȱbelow.

strength,ȱ goodȱ sensoryȱ properties,ȱ easyȱ andȱ rapidȱ

filmȱ formation,ȱ highȱ waterȱ diffusivityȱ andȱ lowȱ

Osmotic Dehydration

soluteȱdiffusivity,ȱandȱmaintenanceȱofȱtheȱcoatingȱinȱ Inȱ theȱ screeningȱ experiments,ȱ byȱ usingȱ differentȱ

anȱ intactȱ stateȱ withoutȱ dissolvingȱ intoȱ theȱ osmoticȱ levelsȱofȱprocessingȱparametersȱinȱCentralȱCompositeȱ

solutionȱ (Camirandȱ et al .ȱ 1992).ȱ Theȱ advantagesȱ ofȱ

OSMEMBȱprocessȱare:ȱhighȱratesȱofȱODȱasȱcomparedȱ

RotatableȱDesignȱ(CCRD),ȱtheȱconditionsȱofȱODȱwereȱ

toȱuncoatedȱsamples,ȱreducedȱlossesȱofȱcolourants,ȱ

optimized.ȱ Theȱ processingȱ parametersȱ optimizedȱ

468