On food and cooking the science and lore of the kitchen ( PDFDrive ) 255

packedtogetherinthecells,theharderitisto
cutacrossthem.Sothemeatofolder,well
exercisedanimalsistougherthanthemeatof
younganimals.
Connective Tissue Connective tissue is the
physicalharnessforalltheothertissuesinthe
body,muscleincluded.Itconnectsindividual
cellsandtissuestoeachother,thusorganizing
and coordinating their actions. Invisibly thin
layers of connective tissue surround each
muscle fiber and hold neighboring fibers
together in bundles, then merge to form the
large, silver-white sheets that organize fiber
bundles into muscles, and the translucent
tendonsthatjoinmusclestobones.Whenthe
fibers contract, they pull this harness of
connective tissue with them, and the harness
pullsthebones.Themoreforcethatamuscle
exerts,themoreconnectivetissueitneedsfor
reinforcement, and the stronger the tissue
needs to be. So as an animal’s growth and


exercise bulk up the muscle fibers, they also
bulkupandtoughentheconnectivetissue.
Connectivetissueincludessomeliving
cells,butconsistsmainlyofmoleculesthat
thecellssecreteintothelargespacesbetween
them.Themostimportantofthesemolecules
forthecookaretheproteinfilamentsthatrun
throughoutthetissueandreinforceit.One,a

proteincalledelastinforitsstretchiness,is
themaincomponentofbloodvesselwallsand
ligaments,andisespeciallytough;itscrosslinkscannotbebrokenbytheheatofcooking.
Fortunatelythereisn’tmuchofitinmost
muscletissue.
Themajorconnective-tissuefilamentis
theproteincalledcollagen,whichmakesup
aboutathirdofalltheproteinintheanimal
body,andisconcentratedinskin,tendons,and
bones.ThenamecomesfromtheGreekfor
“glueproducing,”becausewhenit’sheatedin
water,solid,toughcollagenpartlydissolves
intostickygelatin(p.597).Sounlikethe