Agriculture Reference
In-Depth Information
and 76-77% RH) stored up to seven days before decay and
wilting became apparent. In the United States, passion fruit
is packed in 4.5 and 6 kg cartons, in one- or two-layer trays
(Paull & Chen 2002b).
In Queensland, Australia, interstate certification assur-
ance describes the principles of operation and standards, and
the responsibilities and practices of personnel handling and
grading fruit. The procedure for purple passion fruit (ICA-
15) defines mature green fruit as having skin free from
wrinkling and unbroken skin (i.e. with 'no pre-harvest
crack, puncture, pulled stem or other break that pene-
trates through to the flesh and has not healed with callus
tissue'). Other aspects covered by the procedure include
accreditation, audit, sorting, packing, sampling (selection,
examination, identification and action on nonconformance),
dispatch and record keeping (ICA 2002).
Alternaria alternata
(Fr.) Keissler, causing brown spot in
the Pacific Islands and
A. passiflorae
Simmonds in East
Africa, Australia and Hawaii. The disease is characterised
by circular, sunken light brown spots with a green border. It
is most severe after periods of warm wet weather
(Paull & Chen 2002b). Attack by
Septoria passiflorae
Louw. leads to uneven ripening and fruits that are fit
only for processing. Other fungi found on rotting
passion fruits include species of
Aspergillus
,
Cladosprium
,
Colletotrichum
,
Botryodiplodia
,
Penicillium
,
Phytopthora
,
Rhizopus
,
Fusarium
,
Phomopsis
and
Pestalotiopsis
(Snowdon 1990; Bora & Narain 1997). A
Phytophthora
fruit rot (caused by
P. nicotiana
var.
parasitica
) leads to
water-soaked, dark green lesions that dry on the skin (Kader
2002). Management of fungal diseases before harvest is
achieved through sanitation in the orchard, pruning to
reduce relative humidity and fungicides (Paull & Chen
2002b). Post-harvest control relies on good temperature
and relative humidity control in storage (Kader 2002).
Bacterial spotting is caused by
Pseudomonas syringae
pv.
passiflorae
(Reid) Young, Dye & Wilkie and
Xanthomonas campestris
pv.
passiflorae
(Pereira) Dye
(Snowdon 1990).
Insect pests include the fruit flies
Anastrepha
,
Dacus
and
Ceratitis
. Infestation occurs pre-harvest with damage
becoming apparent as the fruits mature. Control using
irradiation has been successful (Paull & Chen 2002b).
Processing
Processing for juice and pulp production is mechanised. In
Hawaii, fruits from the field are dumped into a wash tank
with agitation. Conveyors lift the fruits past wash sprays
whence they are sorted by hand to remove damaged or
otherwise unfit fruit. Skins are cut with rotating knives
spaced 1.6 cm apart and the sliced pieces fed into a
continuous basket centrifuge. Juice, pulp and seeds pass
through the centrifuge screen while rinds pass to waste.
Screened pulpers and finishers separate the seeds and
fibres from the juice and pulp. In Australia, the juice may
be extracted using rollers; in New Zealand pulp and seeds
are removed from halved fruits using suction (Chan 1980).
Extraction yields have been increased by 35% by using
pectinolytic enzymes (Lipitoa & Robertson 1977). Once
processed, the juice is preserved by heating or freezing.
LYCHEE
Litchi chinensis
Sonn., in the Sapindaceae or soapberry
family, is a dense evergreen tree that reaches 30 m in height
(Mitra 2002). The species is native to the low elevations of
southern China where it is eaten fresh or dried as brown
'litchi nuts'. Production in China dates back at least 4000
years (Ochse
et al
. 1961; Menzel 2002). However, lychee
has only spread relatively recently through Southeast Asia
and the Pacific, reaching Florida in 1883 and Hawaii in
1973 (Anon. 1996). It is now grown commercially in most
Asian countries, and in Australia, Central America and
South Africa, as well as the United States.
The literature on lychee post-harvest is relatively recent,
with much attention focused on new areas of production in
Asia and Australia. Thus the following account draws heavily
on FAO publications by Menzel (2002), and Papademetriou
and Dent (2002) in southern Asia, and Australian govern-
ment reports described by Olesen
et al
. (2003).
Atmosphere modification
Various coatings and wrappings, such as sucrose (Bepete
et al
. 1994) or plastic films (Mohammed 1993), have been
used to extend storage life. Wrapping fruits in VF-60
plastic film prevented water loss and maintained the
external fruit appearance (Arjona
et al
. 1994). The main
beneficial influence of wraps and coatings is probably
due to reduction in water loss rather than any modified
atmosphere effect.
Passion fruits are climacteric and produce large amounts
of ethylene during ripening; peak climacteric rates are
160-400 l kg
−1
h
−1
at 20°C (Shiomi
et al
. 1996).
Post-harvest pathology and entomology
Relatively few pathogens or pests attack passion fruit to
any major degree. The main disease agents are the fungi
International trade
At 2 000 000 metric tonnes, or 95%, Asia accounts for the
bulk of world supply of lychee (Table 12.3) (Menzel 2002).
