On Food and Cooking

them, a pale, spongy mass called the placenta.
(For chillis as vegetables, see p. 331). Their
pungent chemicals, the capsaicins, are only
synthesized by the surface cells of the
placenta, and accumulate in droplets just
under the cuticle of the placenta surface. That
cuticle can split under the pressure and allow
the capsaicin to escape and spread onto the
seeds and the inner fruit wall. Some capsaicin
also seems to enter the plant’s circulation, and
can be found in small quantities within the
fruit wall and in nearby stems and leaves.
The amount of capsaicin that a chilli
contains depends not only on the plant’s
genetic makeup, but on growing conditions —
high temperatures and drought increase
production — and on its ripeness. The fruit
accumulates capsaicin from pollination until
it begins to ripen, when its pungency declines
somewhat: so maximum pungency comes
around the time that the green fruit begins to
change color.