On food and cooking the science and lore of the kitchen ( PDFDrive ) 1516

that generate flavor at high cooking
temperatures (p. 778). Second, many single
aminoacidsandshortpeptideshavetastesof
their own, and in foods where proteins have
been partly broken down — aged cheeses,
cured hams, soy sauce — these tastes can
contribute to the overall flavor. Most tasty
aminoacidsareeithersweetorbittertosome
degree, and a number of peptides are also
bitter. But glutamic acid, better known in its
concentrated commercial form MSG
(monosodium glutamate), and some peptides
haveauniquetastethatisdesignatedbysuch
wordsassavory,brothy, andumami(Japanese
for “delicious”). They lend an added
dimension of flavor to foods that are rich in
them, including tomatoes and certain
seaweedsaswellassalt-curedandfermented
products. When heated, sulfur-containing
aminoacidsbreakdownandcontributeeggy,
meatyaromanotes.


Amino Acids Influence Protein Behavior
The third important characteristic of amino
acids is that they have a variety of chemical
natures, and these influence the structure and
behavioroftheproteinthey’reapartof.Some
amino acids have portions resembling water
and can form hydrogen bonds with other
molecules, including water. Some have short

carbon chains or carbon rings that resemble
fats, and can form van der Waals bonds with
othersimilarmolecules.Andsome,especially
thosethatincludeasulfuratom,areespecially
reactive, and can form strong covalent bonds
with other molecules, including other sulfurcontaining amino acids. This means that a
single protein has many different chemical
environmentsalongitschain:partsthatattract
water molecules, parts that avoid water
molecules, and parts that are ready to form
strong bonds with similar parts on other
proteins,oronotherpartsofthesameprotein.
ProteinStructure