On food and cooking the science and lore of the kitchen ( PDFDrive ) 1513
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andsoofmeats,althoughitsconcentrationat
thetimeofslaughterwillaffecttheultimate
pHofthemeat,andtherebyitstexture(p.
142).
A sugar, glucose, and a polysaccharide,
starch,whichisachainofglucosemolecules.
Plantsproducetwobroadlydifferentformsof
starch: simple long chains called amylose,
and highly branched chains called
amylopectin.
CelluloseCelluloseis,likeamylose,alinear
plantpolysaccharidemadeupsolelyof
glucosesugars.Yetthankstoaminor
differenceinthewaythesugarsarelinkedto
eachother,thetwocompoundshavevery
differentproperties:cookingdissolvesstarch
granulesbutleavescellulosefibersintact;
mostanimalscandigeststarch,butnot
cellulose.Celluloseisastructuralsupport
that’slaiddownincellwallsintheformof
tinyfibersanalogoustosteelreinforcingbars,
andit’smadetobedurable.Fewanimalscan
digestcellulose,andhay-eatingcattleand
wood-eatingtermitescandosoonlybecause
theirgutsarepopulatedbycellulose-digesting
bacteria.Tootheranimals,including
ourselves,celluloseisindigestiblefiber
(whichhasitsownvalue;seep.258).
HemicellulosesandPecticSubstancesThese
polysaccharides(madefromavarietyof
sugars,includinggalactose,xylose,arabinose)
arefoundtogetherwithcelluloseintheplant
cellwalls.Ifthecellulosefibrilsarethe
reinforcingbarsinthecellwalls,the
amorphoushemicellulosesandpectic
substancesareasortofjelly-likecementin
whichthebarsareembedded.Their
significanceforthecookisthat,unlike
