On Food and Cooking

fruit in a paper bag with an ethylene-emitting
banana. If these warm-climate fruits are
refrigerated while unripe, their cellular
machinery is damaged and they will never
ripen; once ripe, however, they can be
refrigerated for several days and retain their
quality. The aroma of avocado comes mainly
from a group of mildly spicy terpenes
including woody caryophyllene, as well as
unusual 10-and 7-carbon fragments of fatty
acids.
The flesh of rich avocado varieties readily
turns into an unctuous puree without the
necessity of any cooking, while leaner
varieties retain some crispness and hold up
well in sliced form for salads. Avocado flesh
is well known for browning rapidly once cut
or mashed (p. 269), a problem that can be
remedied by adding an acidic ingredient
(often lime juice) or by airtight wrapping with
a plastic film that blocks oxygen effectively
(polyvinylidene chloride, alias saran, is far