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On food and cooking the science and lore of the kitchen ( PDFDrive ) 881

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theseed”)isoftentheonlypartofthegrain
consumed.Itconsistsofstoragecellsthat
containstarchgranulesembeddedinamatrix
ofprotein.Thismatrixismadeupofnormal
cellproteinsandmembranematerials,and
sometimesofsphericalbodiesofspecial
storageproteinswhich,squeezedtogetheras
thestarchgranulesgrow,losetheirindividual
identityandformamonolithicmass.There’s
generallymorestarchandlessproteinpercell
nearthecenterofthegrainthanthereisnear
thesurface.Thisgradientmeansthatthemore
grainsarerefinedbymillingandpolishing,
thelessnutritioustheyget.
MillingandRefining

Peoplebegantreatingthegrainstoremove
theirtoughprotectivelayersinprehistoric
times.Millingbreaksthegrainsintopieces,
andrefiningsiftsawaythebranandgerm.The
verydifferentmechanicalpropertiesof


endosperm,germ,andbranmakethis
separationpossible:thefirstiseasily
fragmented,andtheothersareoilyand
leatheryrespectively.Thegermandthebran
—whichinpracticeincludethealeurone
layerjustunderneathit—togetheraccount
formostofthefiber,oil,andBvitamins
containedinthewholegrain,aswellassome


25%ofitsprotein.Yetthesepartsofthegrain
areusuallyremovedentirelyorinpartfrom
riceandbarleygrains,andfromcornmealand
wheatflours.Whythiswaste?Refinedgrains
areeasiertocookandtochew,andmore
attractivelylightincolor.Andinthecaseof
flours,thehighlipidconcentrationsinthe
germandaleuronelayershortentheshelflife
ofwhole-grainflourssubstantially.Theoils
aresusceptibletooxidationanddevelop
rancidflavors(stalearoma,harshtaste)ina
matterofweeks.Todaymostrefinedcereals
inindustrialcountriesarefortifiedwithB
vitaminsandironinordertocompensatefor



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