Mechanical properties of onion seeds ( Allium cepa variety aggregatum L.)

forȱtheȱcoefficientȱofȱdeterminationȱofȱR²ȱ=ȱ0.9783

minimumȱvalueȱisȱrecordedȱalongȱlength.ȱTheȱleastȱ

ruptureȱforcesȱatȱhigherȱmoistureȱcontentȱmightȱhaveȱ

M ₁₀₀₀ =ȱ0.3225xȱ+ȱ0.5145ȱ(R²ȱ=ȱ0.9783)

resultedȱfromȱtheȱfactȱthatȱtheȱonionȱseedȱseemedȱtoȱ

Aȱ similarȱ increasingȱ trendȱ hasȱ beenȱ reportedȱ byȱ beȱveryȱsoftȱtextureȱatȱhighȱmoistureȱcontent.ȱSimilarȱ

Pandiselvamȱ et al. ȱ(2014)ȱforȱonionȱseeds,ȱVisvanathanȱ resultsȱ wereȱ reportedȱ byȱ Aydinȱ (2002),ȱ Altunasȱ

et al. ȱ(1996)ȱforȱneemȱnut,ȱSacilikȱ et al. ȱ(2003)ȱforȱhempȱ andȱYildizȱ(2007)ȱandȱAltunasȱandȱErkolȱ(2010)ȱforȱ

seed,ȱSinghȱandȱGoswamiȱ(1996)ȱforȱcumin,ȱVilcheȱ et

walnutsȱandȱpistachioȱnuts,ȱrespectively.

al. ȱ(2003)ȱforȱquinoaȱandȱYalcınȱandȱOzarslanȱ(2004)ȱ

forȱvetch.

Mathematicalȱcorrelationsȱwereȱestablishedȱbetweenȱ

moistureȱcontentȱandȱruptureȱforceȱofȱonionȱseedsȱ

Mechanical properties of onion seeds

compressedȱalongȱlength,ȱbreadthȱandȱthicknessȱareȱ

representedȱasȱfollows:

Theȱ mechanicalȱ propertiesȱ likeȱ initialȱ ruptureȱ

force,ȱ peakȱ forceȱ requiredȱ forȱ deformation,ȱ energyȱ

Lȱ=ȱ628.57x 2ȱ -ȱ166.74xȱ+ȱ12.033ȱR²ȱ=ȱ0.9974

absorbedȱ duringȱ ruptureȱ andȱ distanceȱ movedȱ atȱ Bȱ=ȱ1525x 2ȱ -ȱ339.9xȱ+ȱ22.499ȱR²ȱ=ȱ0.9579

ruptureȱ areȱ determinedȱ asȱ perȱ theȱ proceduresȱ

mentionedȱinȱMaterialsȱandȱMethodsȱandȱtheȱresultsȱ

Tȱ=ȱ544.64x 2ȱ -ȱ174.39xȱ+ȱ15.155ȱR²ȱ=ȱ0.9661

areȱrepresentedȱasȱfollows

Itȱisȱobservedȱfromȱtheȱfigureȱthatȱhighestȱruptureȱ

forceȱisȱrequiredȱwhenȱtheȱseedȱisȱkeptȱalongȱbreadthȱ

Dimension and mass of onion seeds at different moisture

wise.ȱAtȱaȱmoistureȱcontentȱofȱ7%,ȱitȱhasȱrecordedȱaȱ

contents

maximumȱruptureȱforceȱofȱ9.65ȱNȱandȱaȱminimumȱ

ofȱ3.82ȱNȱatȱ15%ȱm.cȱ(db).ȱTheȱinitialȱruptureȱforceȱ

Moisture content,% (db)

isȱminimumȱwhenȱtheȱseedȱsampleȱisȱloadedȱalongȱ

Properties

7

9

11

13

15

lengthȱ wiseȱ whenȱ comparedȱ toȱ compressionȱ alongȱ

Major axes (mm)

2.677

2.731 2.813 2.845 2.91

breadthȱ andȱ thicknessȱ wise.ȱ Theȱ valueȱ ofȱ 5.82ȱ andȱ

Minor axes (mm)

1.929

2.048 2.092 2.138 2.244

0.93ȱ Nȱ wereȱ recordedȱ atȱ aȱ moistureȱ contentȱ ofȱ 7ȱ

andȱ15%ȱm.cȱ(db),ȱrespectively.ȱThisȱresultȱisȱhighlyȱ

Intermediate

axes

1.408

1.471 1.488 1.504 1.538

(mm)

dependentȱonȱtheȱstructureȱofȱtheȱseedȱsample.

GMD (mm)

1.937

2.01

2.06

2.09

2.16

Peak force at deformation

Sphericity, ( ɸ )

0.726

0.732 0.736 0.740 0.745

Theȱ meanȱ valueȱ forȱ theȱ deformationȱ atȱ peakȱ forceȱ

M 1000, g

2.91

3.30

4.05

4.53

5.52

isȱrepresentedȱinȱtheȱTableȱ2ȱandȱFigureȱ5.ȱItȱisȱseenȱ

Rupture force

fromȱ theȱ tableȱ thatȱ deformationȱ occurredȱ atȱ peakȱ

forceȱ isȱ highestȱ (77.81N)ȱ alongȱ breadthȱ wiseȱ andȱ

Theȱ seedȱ ruptureȱ observedȱ atȱ differentȱ moistureȱ

leastȱ (35.61N)ȱ alongȱ lengthȱ wise.ȱ Theȱ highestȱ andȱ

contentȱ levelsȱ alongȱ threeȱ mutuallyȱ perpendicularȱ

lowestȱvaluesȱwereȱobtainedȱatȱlowestȱandȱhighestȱ

directionsȱ areȱ representedȱ asȱ shownȱ inȱ theȱ Figureȱ

moistureȱcontents.ȱItȱisȱalsoȱevidentȱfromȱtheȱfigureȱ

1.ȱTheȱfigureȱclearlyȱindicatesȱtheȱforceȱrequiredȱtoȱ

thatȱtheȱpeakȱforceȱdecreasesȱasȱtheȱmoistureȱcontentȱ

initiateȱtheȱruptureȱisȱhighlyȱdependentȱonȱmoistureȱ

increasesȱalongȱallȱtheȱthreeȱaxes.ȱTheȱvaluesȱalongȱ

contentȱasȱitȱincreasesȱfromȱ7ȱ-15%,ȱ(db).ȱTheȱinitialȱ

length,ȱ breadthȱ andȱ thicknessȱ decreasedȱ fromȱ

ruptureȱforceȱvalueȱrangedȱfromȱ5.28ȱtoȱ0.93,ȱ9.65ȱtoȱ

35.61ȱ toȱ 22.85,ȱ 77.18ȱ toȱ 48.01ȱ andȱ 74.23ȱ toȱ 42.79ȱ Nȱ

3.82ȱ andȱ 8.04ȱ toȱ 1.38ȱ Nȱ alongȱ length,ȱ breadthȱ andȱ

asȱtheȱmoistureȱincreasedȱfromȱ7ȱtoȱ15%,ȱm.cȱ(db).ȱ

thickness,ȱrespectively.ȱItȱisȱevidentȱfromȱtheȱfigureȱ

Mathematicalȱrelationshipȱbetweenȱmoistureȱcontentȱ

thatȱmuchȱforceȱisȱrequiredȱtoȱinitiateȱtheȱruptureȱatȱ

andȱpeakȱforceȱatȱdeformationȱisȱexpressedȱinȱtermsȱ

lowerȱmoistureȱcontent.ȱTheȱmaximumȱforceȱrequiredȱ

ofȱregressionȱequationȱasȱfollows

toȱinitiateȱtheȱruptureȱisȱalongȱtheȱbreadthȱandȱtheȱ

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