Mass Transfer Kinetics during Osmotic Dehydration of Pineapple Samples Coated with Pectin
uncoatedȱ samples.ȱ Theȱ highestȱ WRȱ (39.80ȱ g/100ȱ gȱ laterȱ onȱ dryingȱ forȱ 10ȱ min.ȱ Comparingȱ theȱ meanȱ
freshȱ sample)ȱ wasȱ observedȱ inȱ pineappleȱ samplesȱ valuesȱofȱdippingȱtime,ȱthereȱwasȱsmallȱincreaseȱinȱ
dippedȱinȱcoatingȱsolutionȱofȱ1%ȱconcentrationȱforȱ WRȱvalueȱbyȱincreasingȱtheȱdippingȱtimeȱfromȱ60ȱtoȱ
120ȱsȱfollowedȱbyȱovenȱdryingȱforȱ10ȱminȱwhileȱtheȱ 120ȱs.ȱSimilarly,ȱwhenȱtheȱmeanȱvaluesȱofȱtwoȱdryingȱ
lowestȱWRȱ(26.97ȱg/100ȱgȱfreshȱsample)ȱwasȱfoundȱinȱ timeȱ wereȱ compared,ȱ WRȱ valueȱ decreasedȱ fromȱ
samplesȱdippedȱforȱ120ȱsȱinȱcoatingȱsolutionȱofȱ5%ȱ 35.27ȱtoȱ34.16ȱ(g/100ȱgȱfreshȱsample)ȱwithȱincreaseȱ
concentrationȱ andȱ laterȱ onȱ ovenȱ driedȱ forȱ 40ȱ min.ȱ inȱ theȱ dryingȱ timeȱ fromȱ 10ȱ toȱ 40ȱ min.ȱ Statisticalȱ
TheȱvalueȱofȱWRȱofȱuncoatedȱsampleȱwasȱfoundȱtoȱ analysisȱshowedȱthatȱWRȱvaluesȱatȱallȱtheȱlevelsȱofȱ
beȱ32.10ȱ(g/100ȱgȱfreshȱsample).
concentration,ȱ twoȱ dippingȱ timeȱ andȱ twoȱ dryingȱ
Theȱ WRȱ valuesȱ ofȱ allȱ theȱ coatedȱ samples,ȱ whichȱ
timeȱdifferȱsignificantlyȱfromȱoneȱanother.ȱTheȱvaluesȱ
wereȱdippedȱinȱtheȱcoatingȱsolutionȱofȱconcentrationȱ
ofȱWRȱofȱtheȱentireȱcoatedȱsamplesȱwereȱstatisticallyȱ
rangingȱfromȱ0.5ȱtoȱ3%ȱwereȱmoreȱthanȱtheȱuncoatedȱ
differentȱfromȱtheȱuncoatedȱsampleȱ(p<0.05).
sample.ȱTheȱvaluesȱofȱWRȱofȱcoatedȱsamplesȱwereȱ
Conclusion
lessȱ thanȱ theȱ uncoatedȱ sampleȱ whenȱ theȱ samplesȱ
wereȱcoatedȱinȱtheȱsolutionȱofȱ4%ȱconcentrationȱorȱ Theȱ concentrationȱ ofȱ coatingȱ solution,ȱ dippingȱ
aboveȱatȱbothȱtheȱdippingȱandȱdryingȱtime.ȱItȱwasȱ timeȱ andȱ dryingȱ timeȱ showedȱ significantȱ effectȱ
desiredȱthatȱWLȱshouldȱbeȱmaximumȱandȱSGȱshouldȱ onȱ theȱ WL,ȱ SG,ȱ PRȱ andȱ WRȱ duringȱ ODȱ process.ȱ
beȱ minimumȱ duringȱ theȱ massȱ transferȱ toȱ achieveȱ WLȱ increasedȱ upȱ toȱ 2%ȱ levelȱ ofȱ concentrationȱ ofȱ
maximumȱWRȱvaluesȱinȱtheȱcoatedȱsamples.ȱIncreaseȱ coatingȱ solutionȱ andȱ thenȱ decreasedȱ withȱ furtherȱ
inȱtheȱconcentrationȱofȱcoatingȱsolutionȱfromȱ0.5ȱtoȱ increaseȱinȱtheȱconcentration.ȱWLȱofȱcoatedȱsamplesȱ
1%ȱledȱtoȱincreaseȱinȱWRȱvaluesȱatȱaȱdryingȱtimeȱofȱ wasȱ moreȱ thanȱ theȱ uncoatedȱ sampleȱ onlyȱ upȱ toȱ
10ȱminȱafterȱdippingȱtheȱsamplesȱforȱbothȱ60ȱandȱ120ȱ 3%ȱ concentrationȱ showingȱ highȱ concentrationȱ ofȱ
s.ȱWRȱvaluesȱstartedȱdecreasingȱwithȱfurtherȱincreaseȱ coatingȱsolutionȱresultedȱinȱmoistureȱbarrierȱduringȱ
inȱconcentrationȱtoȱ2%ȱorȱabove.ȱOnȱtheȱotherȱhand,ȱ OD.ȱSGȱdecreasedȱupȱtoȱ1%ȱconcentrationȱandȱthenȱ
whenȱtheȱdryingȱtimeȱwasȱincreasedȱtoȱ40ȱmin,ȱtheȱ increasedȱupȱtoȱ5%ȱconcentration,ȱbutȱSGȱofȱallȱtheȱ
increaseȱinȱWRȱvaluesȱwasȱobservedȱfromȱ0.5ȱtoȱ2%ȱ coatedȱsamplesȱwereȱlessȱthanȱtheȱuncoatedȱsamples.ȱ
afterȱdippingȱtheȱsamplesȱforȱbothȱ60ȱandȱ120ȱs.ȱWRȱ IncreaseȱinȱdippingȱtimeȱledȱtoȱdecreaseȱinȱWL.ȱSGȱ
valuesȱdecreasedȱwhenȱtheȱconcentrationȱofȱcoatingȱ decreasedȱbyȱincreasingȱbothȱtheȱdippingȱandȱdryingȱ
solutionȱ wasȱ furtherȱ increasedȱ toȱ 3%ȱ orȱ above.ȱ time.ȱ PRȱ wasȱ observedȱ highestȱ inȱ thoseȱ samples,ȱ
Therefore,ȱ1%ȱconcentrationȱwasȱconsideredȱbestȱatȱ whichȱwereȱdippedȱforȱ120ȱsȱinȱcoatingȱsolutionȱofȱ
aȱdryingȱtimeȱofȱ10ȱminȱandȱ2%ȱconcentrationȱwasȱ 1%ȱpectinȱsolutionȱandȱlaterȱovenȱdriedȱforȱ40ȱmin.ȱ
consideredȱbestȱwhenȱtheȱovenȱdryingȱtimeȱwasȱ40ȱ Overall,ȱcoatingȱresultedȱinȱsubstantiallyȱdecreasedȱ
min.
solidȱuptakeȱwhileȱmaintainingȱtheȱamountȱofȱWL.
Consideringȱ theȱ meanȱ valuesȱ ofȱ allȱ theȱ sixȱ
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