On food and cooking the science and lore of the kitchen ( PDFDrive ) 1199

Freshoutoftherefrigerator,thevariousyolk
particlesmoveonlysluggishlyanddon’tcoat
the fat droplets as quickly and completely.
When yolks are cooked, the proteins unfold
andcoagulate,thusendingtheirusefulnessas
flexible surface coatings. Hard-cooked yolks
are sometimes used instead of raw yolks to
makeemulsifiedsauces;theirdisadvantageis
that the proteins have been coagulated in
place and phospholipids probably trapped in
thecoagulatedparticles,sotheyhavefarless
emulsifying power, and the yolk texture can
giveasubtlegraininess.
Andeggwhites?They’realess
concentratedsourceofprotein,anddesigned
forafat-free,wateryenvironment,and
thereforeoflittlehelpincoatingfatdroplets.
However,thewhiteproteinsprovidesome
viscositythankstotheirlargesizeandloose
associationswitheachother,sotheyhave
somevalueasemulsionstabilizers.


Oildropletsinmayonnaise.Aviewthroughan
electron microscope. Protein and emulsifier
molecules and aggregates, all from egg yolk,
arepresentbetweenthelargedropletsandon
their surfaces, and help prevent them from
coalescing.
ColdEggSauces:Mayonnaise

Mayonnaiseisanemulsionofoildroplets
suspendedinabasecomposedofeggyolk,
lemonjuiceorvinegar,water,andoften
mustard,whichprovidesbothflavorand
stabilizingparticlesandcarbohydrates(p.
417).It’sthesaucemosttightlypackedwith
oildroplets—asmuchas80%ofitsvolume