Postharvest Biology and Technology of Fruits, Vegetables, and Flowers

16 POSTHARVEST BIOLOGY & TECHNOLOGY OF FRUITS, VEGETABLES, & FLOWERS
2.5.4 Cucurbits
Cucurbits are another major group of vegetables belonging to Cucurbitaceae that are cultivated
widely in the tropics and subtropics. The fruits are varied in nature, but all originate
from an inferior ovary. Some cucurbits such as the cucumber (Cucumis sativus) and melons
(Cucumis melo) are consumed raw. The melons are fruits rather than vegetables. There
are several varieties of gourds and squashes. Some of these include wax gourd (Benincasa
hispida), bitter gourd (melon) (Momordica charantia), squash (zucchini—Cucumis pepo),
winter squash (butternut squash—Cucumis moschata; turban squash and buttercup squash—
C. maxima var. turbaniformis; banana squash—C. maxima), pumpkin (C. pepo), and
sphaghetti squash (C. pepo). Chayote (Sechium edule) is common in Mexico and Central
America. The ripened pumpkins, squashes, and some cucumbers can be stored for
months in a cool dry place. The cucurbits are chilling sensitive and low-temperature storage
is not required. The bitter gourd, as the name suggests, is very bitter and does not store well.
Water loss is a problem even at low temperature, and the vegetable is best used within a
week of harvest. In general, young immature fruits are harvested for consumption. Several
cucurbits are considered to have medicinal properties such as the bitter gourd (against type
2 diabetes).
2.5.5 Solanaceous vegetables
Several members of Solanaceae are important vegetables, though the family is associated
with poisonous alkaloids. The major solanaceous vegetable crops include tomato (Solanum
lycopersicum, formerly Lycopersicon esculentum), potato (Solanum tuberosum), eggplant
(Solanum melongena), and sweet and hot peppers (Capsicum annuum). The eggplants are
consumed when young and never used after ripening, whereas tomatoes are used after
ripening. The peppers can be used before or after ripening depending on the type. Potato
is the exception in this family, and the edible part is the stem tuber. Solanaceous fruits do
not store very well. In general, a postharvest life of 7–10 days can be anticipated during
refrigerated storage. Potatoes, on the other hand, can be stored for months covered with dry
soil in a cool place or under a controlled atmosphere at a low temperature.
2.5.6 Compositae vegetables
The family of Compositae (Asteraceae) includes several leafy vegetables. Some of these
include wild chicory or endive (Cichorium intybus), curly chicory (Cichorium endivia), lettuce
(Lactuca sativa), and artichoke (Cyanara scolymus). Jerusalem artichoke (Helianthus
tuberosus) is an exception and produces an edible tuber, though not widely used at present.
Lettuce is one of the most popular vegetables. There are several varieties of lettuce including
the head lettuce, butterhead lettuce, leaf lettuce, and romaine lettuce. The shelf life of leafy
vegetables is low. These can best be stored in perforated plastic bags in the refrigerator
for a week. Leaf and romaine lettuce should be washed to get rid of the soil and excess
moisture removed before storing. Some varieties such as Boston lettuce and iceberg lettuce
are very fragile and are washed just before consumption. They can be stored in an airtight
compartment in the refrigerator and should not be kept together with ethylene-producing
fruits since the ethylene tends to promote browning in lettuce.