Agriculture Reference
In-Depth Information
of 5 -10 C, depending on cultivar and production area.
Storage at lower temperature may induce chilling injury
depending on cultivar, ripeness stage, and temperature and
storage duration. Storage at lower humidity results in more
severe symptoms of rib browning.
Carambolas have been shipped successfully without re-
frigeration from Florida to northern cities in avocado lugs
lined and topped with excelsior. The fruits are packed
solidly, stem-end down, at a 45 angle, the flanges of one
fruit fitting into the 'V' grooves of another (Morton, 1987).
relish may be made of chopped unripe fruits combined with
horseradish, celery, vinegar, seasonings, and spices (Mor-
ton, 1987). Fresh-cut sweet carambolas can be stored at 4 C
for 6 weeks in vacuum-packed films (oxygen permeability
value of 300 cc/m 2 /24 hours or less) with satisfaction in
color, texture, flavor, and safety (Matthews et al., 1989).
However, they brown readily within 6 hours when exposed
to air. Treating carambola slices with 1 or 2.5% citric acid
in combination with 0.25% ascorbic acid prior to packag-
ing is very effective in controlling browning (Weller et al.,
1997). In 2003, Teixeira et al. determined the effects of
postcutting chemical treatments, atmospheric modification,
and their combinations on the shelf life of carambola (cv.
'Maha') slices and reported that carambola slices treated
with 1% ascorbic acid and stored in a controlled atmosphere
of 0.4% O 2 had no significant browning or loss in visual
quality for up to 12 days. Teixeira et al. (2004) investigated
suitable stage of maturity to produce fresh-cut carambola
(cv. 'Fwang Tung') products and found that mature-green
(50% yellow) stage was more suitable for fresh-cut produc-
tion when compared to the mature (100% yellow) stage,
owing to a higher resistance to cutting, and presenting a
better color and appearance. Quality of the product can be
maintained for up to 9 days. Teixeira et al. (2007) evalu-
ated postharvest changes in carambola (cv. 'Fwang Tung')
slices stored at 6.8 C and 90% RH in polyethylene tereph-
thalate (PET) trays (Neoform R
Controlled atmospheres storage
Fruits held at 7 C in 2.2-4.2% O 2 with 8-8.2% CO 2 retain
color and firmness more than those stored in air (Revel
and Thompson, 1994). Sealed polyethylene film bags delay
degreening and have no effect on flavor after 1 week at 20 C
on either green- or full-colored fruit (Wan and Lam, 1984)
when the final CO 2 content in the bag is 2.5-4.5% and O 2 is
about 15%. Waxing also delays water loss and degreening
(Vines and Grierson, 1966). Florida carambolas can be kept
in air at 5 C for 4-6 weeks, provided that the water loss is
minimized by high relative humidity and/or packaging film
barriers (Kader, 2009a).
Disinfestation
Carambola is a fruit fly host, and thus disinfestation is re-
quired by many importing countries. Florida carambola,
which is shipped to California, Arizona, Texas, and certain
export markets, must be certified free of the Caribbean fruit
fly (CFF), Anastrepha suspensa (Loew). Immersing caram-
bolas ('Arkin' and other sweet cultivars) into a heated water
bath at 46.0 -46.4 C for 45 min was sufficient to control
CFF (Hallman and Sharp 1990). However, such heat treat-
ments significantly reduced the shelf life of carambola.
Miller and McDonald (2000) investigated the effectiveness
of various cooling methods following heat treatment to al-
leviate injury of carambola by heat stress and found that
the fruit cooled with refrigerated air had the least injury
compared with other cooling methods, while ice-cooling
resulted in severe quality degradation. Currently irradia-
tion and a cold treatment (14 days at 1 C) have been rec-
ommended as disinfestation methods for carambola (Paull
and Ketsa, 2004).
N94), polystyrene trays
covered with PVC 0.017 mm (Vitafilm R
, Goodyear), and
vacuum-sealed polyolefin bags (POL, Cryovac R
PD900)
and reported that storage in POL helped reduce degreening
and PPO activity, resulting in better appearance for up to
12 days. PET trays and PVC film did not significantly mod-
ify the internal atmosphere and the high water permeability
of PVC led to more rapid slice desiccation.
PROCESSING AND PROCESSED
PRODUCTS
Besides being eaten fresh, carambola can be processed
into various products. The sweet carambolas are mainly
for direct consumption, unfermented juice, and refriger-
ated slices, while the tart carambolas are often processed
into dehydrated slices, preserves, jam, jelly, pickles, sweet-
ened nectar, and fermented drink (Wu et al., 2004). In China
and Taiwan, carambolas are sliced lengthwise and canned
in syrup for export. In Thailand, most of carambolas pro-
duced are eaten fresh, while a small number are processed
into dried carambolas and carambola candy. Examples of
processed carambola products in Thailand and Taiwan are
shown in Figs. 12.4 and 12.5.
MINIMALLY OR FRESH-CUT PRODUCTS
Consumption of fresh-cut products has increased in the
last few years, mainly due to demand for quality, con-
venience, and safety. The star shape in cross section of
carambola is very attractive to consumers. Ripe carambo-
las can be sliced and served in salads or used as garnish. A
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