On food and cooking the science and lore of the kitchen ( PDFDrive ) 1002

kerneldownintosmallparticles,andsifting
theparticlestomakeaflourofthedesired
qualities.Mostfloursarerefined:thatis,they
havebeensievedtoremovethegermandbran
layersfromtheparticlesofprotein-and
starch-richendosperm.Branandgermarerich
innutrientsandflavor,buttheygorancidina
fewweeks,andinterferephysicallyand
chemicallywiththeformationofa
continuous,stronggluten;sowhole-grain
floursmakedenser,darkerbreadsand
pastries.Inconventionalmilling,grooved
metalrollersshearopenthegrain,squeezeout
thegerm,andscrapetheendospermawayto
beground,sieved,andregrounduntilthe
particlesreachthedesiredsize.Stone
grinding,whichismuchrarer,crushesthe
wholegrainmorethoroughlybeforesieving,
sothatsomeofthegermandbranendupin
eventherefinedflours.Stone-groundflouris
thereforemoreflavorfulthanconventionally
milledflour,butalsohasashortershelf-life.


Improving and Bleaching Bakers have
known for a long time that freshly milled
flourmakesaweakgluten,aslackdough,and
adenseloaf.Astheflouragesforafewweeks
in contact with the air, its gluten and baking
properties improve. We understand now that
oxygenintheairgraduallyfreestheglutenin

proteins’endsulfurgroupstoreactwitheach
otherandformeverlongerglutenchainsthat
give the dough greater elasticity. Beginning
around 1900, millers began to save time,
space, and money by supplementing freshly
milled flour with oxidizing chlorine gas and
then with potassium bromate. However,
worries about the potential toxicity of
bromate residues in the late 1980s led most
millerstoreplacebromatewithascorbicacid
(vitamin C) or azodicarbonamide. (Ascorbic
acid itself is an antioxidant, but becomes
oxidized to dehydroascorbic acid, which in
turn oxidizes the gluten proteins.) In Europe,
fava bean flour and soy flour have been used