foods, some fruits and vegetables do contain
significant quantities of glutamic acid, the
active portion of MSG. Notable among them
are tomatoes, oranges, and many seaweeds.
The glutamic acid in tomatoes, together with
its balanced sweetness and acidity, may help
explain why this fruit is so successfully used
as a vegetable, both with meats and without.
Touch: Astringency Astringency is neither a
taste nor an aroma, but a tactile sensation: that
dry, puckery, rough feeling that follows a sip
of strong tea or red wine, or a bite into an
unripe banana or peach. It is caused by a
group of phenolic compounds consisting of 3
to 5 carbon rings, which are just the right size
to span two or more normally separate protein
molecules, bond to them, and hold them
together. These phenolics are called tannins
because they have been used since prehistory
to tan animal hides into tough leather by
bonding with the skin proteins. The sensation