Longan and Carambola - Tropical and Subtropical Fruits: Postharvest Physiology, Processing and Packaging - page 224

reported in different countries. In India, the ripe fruit is
administered to halt hemorrhages and to relieve bleeding
hemorrhoids, while the dried fruit or the juice may be taken
to counteract fevers. Carambola preserve is believed to al-
leviate biliousness and diarrhea and to relieve a “hangover”
from excessive indulgence in alcohol. Carambola salve is
employed to relieve eye afflictions. In Brazil, the caram-
bola is recommended as a diuretic in kidney and bladder
complaints and is believed to have a beneficial effect in
the treatment of eczema. In China, carambola is used for
quenching thirst and to increase salivary secretion and thus
relieve fever (Morton, 1987). Azeem et al. (2010) reported
that the aqueous extract of the carambola fruit had a hepato-
protective effect against carbon tetrachloride-induced liver
damage in mice.

Shriveling
Shriveling symptoms become visible when the carambolas
lose about 5% or greater of their weight due to water stress
(Kader, 2009a).

Heat damage
Exposure to heat treatments, such as 46 ◦ C for 35-55 min
during quarantine treatments, could result in skin browning
and flesh softening. Better alternatives may be cold treat-
ment and/or irradiation (Kader, 2009a).

Pathological disorders
Anthracnose ( Colletotrichum gloeosporioides )ismost
common, and the symptoms are thin, light brown patches on
fruit edges (Watson et al., 1988). Other postharvest diseases
of carambolas may be caused by Altenraria alternata (es-
pecially on chilled fruits), Cladosporium cladosporioides,
or Botryodiplodia theobromae. The decay usually occurs at
physically damaged sites on the fruits during storage. Min-
imizing physical damage throughout the harvesting and
postharvest handling operations and prompt cooling to 5 ◦ C
can greatly reduce the incidence and severity of postharvest
diseases (Kader, 2009a).

POSTHARVEST PHYSIOLOGY AND
STORAGE TECHNOLOGIES

Respiration and ethylene production
Carambola has a nonclimacteric respiratory pattern. The
respiration rate of 5-10 ml CO 2 /kg/hr at 5 ◦ C, 8-15 ml CO 2 /
kg/hr at 10 ◦ C, 12-18 ml CO 2 /kg/hr at 15 ◦ C, and
20-40 ml CO 2 /kg/hr at 20 ◦ C and were reported by Kader
(2009a). Carambola produces relatively low concentrations
of ethylene after harvest. The low ethylene production rate
of carambola as < 0.1 μ lC 2 H 4 /kg/hr at 20 ◦ C was also re-
ported by Kader (2009a). Exposure to 100 ppm of ethy-
lene for 24 hours can slightly accelerate the disappearance
of green color of carambolas and improvement in flavor
due to loss of acidity during storage at 15 ◦ Cor20 ◦ C, but
such treatment may increase decay incidence and severity
(Kader, 2009a).

Precooling
Prior to transportation and storage, carambola should be
subjected to precooling to reduce field heat as well as res-
piration and transpiration rates. Precooling to 4 ◦ to 10 ◦ C
by forced-air or room cooling is a recommended practice
for carambola (Paull and Chen, 2005).

Optimum storage conditions
Campbell (1989) reported that an adequate storage con-
dition for fresh carambolas is at 5 ◦ C and 85-95% rel-
ative humidity. According to Crane (1994), fruit can be
stored for about 21 days at 5 ◦ to 10 ◦ C and 85-95% rela-
tive humidity without cold damage or any significant loss
in fruit quality. Fruit stored at color break will develop
normal color after they are transferred to room tempera-
tures (22 ◦ -23 ◦ C). Florida carambolas picked when show-
ing the first signs of yellowing kept good condition for
4 weeks at 10 ◦ C; 3 weeks at 15.56 ◦ C; and 2 weeks at
21.1 ◦ C. Waxing extends storage life and preserves the vita-
min value (Morton, 1987). McMahon (2003) reported that
carambola stores well in refrigerated conditions. Fruit can
be stored for up to 5 weeks at 10 ◦ C and for 10 weeks at 5 ◦ C
without loss of flavor. Kader (2009a) suggested that recom-
mended optimum storage conditions for carambola should
be at a relative humidity of 90-95% and a temperature

Physiological and physical disorders
Chilling injury
Symptoms of chilling injury include surface pitting (pits
are either small [ 1 mm], deep, and dark brown or large

[1-2 mm], superficial, and light brown) and rib-edge
browning. These symptoms have been reported in some
carambola cultivars after 2 weeks at 0 ◦ C or 6 weeks at 5 ◦ C,
followed by 2 days at 20 ◦ C (Kader, 2009a).

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Physical injury
Rib-edge and stem-end browning can result from surface
abrasions and other types of bruising. The browning inten-
sity increases with water loss from the fruits. To reduce
postharvest losses, handling carambolas with care to mini-
mize bruising is necessary (Kader, 2009a).