Pineapple - Tropical and Subtropical Fruits: Postharvest Physiology, Processing and Packaging - page 330

Pink disease
This is a bacterial infection suspected to be caused by Aceto-
bacter aceti, Erwinia herbicola, or Gluconobacter oxydans.
The bacteria are carried by insects to the open flowers, and
under favorable conditions, they infect the ovary and reach
the fruit flesh (Hine, 1976). Cha et al. (1997) showed that
Pantoea citrea was the causal agent of pink disease. This
organism causes the typical symptom of red-rusty brown to
black coloration of the fruit tissue when heated during can-
ning. In contrast to the other fruit diseases, the economic
significance of pink disease is the inability to detect asymp-
tomatic diseased fruit prior to processing, with the result of
brown to black slices occurring in sealed cans (Rohrbach
and Johnson, 2003). This disease can be controlled by har-
vesting the fruit before completely ripe, by promoting fruit
production in season unfavorable to the disease develop-
ment, or by dusting the fruits with insecticides such as
Disulfoton during the open-flower stage (Kontaxis, 1978)
as insects are thought to play a role in disseminating the
pathogen from flower to flower. Biological control ( Bacil-
lus gordonae 2061R) further reduces disease incidence in
combination with insecticides (Cha et al., 1994).

pineapple was exported from Hawaii to the US mainland, it
had to be vapor heated at 44.4 ◦ C for 8.75 min and immedi-
ately cooled (Hawaii-Ag, 2008) or chemical fumigated with
methyl bromide. The Animal and Plant Health Inspection
Service (APHIS) has also approved the use of irradiation
to target specific pests (e.g., fruit flies) in all fruits and veg-
etables. Therefore pineapples from Thailand can be treated
with 150 Gy prior to shipping for fruit flies. A 400 Gy dose
is approved to treat all plant pests of the class insecta, except
pupae and adults of the order Lepidoptera, and inspection is
required. New chemical fumigants, such as BOC Limited's
Vapormate (16.7% ethyl formate in CO 2 ), is being evalu-
ated for controlling mites and mealybugs on pineapples and
bananas in the Philippines (Ryan et al., 2006).

FRESH-CUT PINEAPPLE
Modern consumers demand and increasingly buy “ready-
to-eat” products to save time without abandoning a healthy
diet. The dynamism of the fresh pineapple market is linked
to the recent development of fresh-cut pineapple products
(FAO, 2009b). Cut pineapples ranked the highest of all
tropical fruits in quantity and dollars sold in the value-
added category for US fresh fruit in supermarkets (Cook,
2007). This product is usually marketed as slices or cubes.
Nevertheless, rapid deterioration of minimally processed
fruits is a limitation. Peeling and cutting exacerbate the
problem as metabolic activity increases; cellular compart-
mentation is lost bringing together enzymes and substrates
that cause product darkening and softening; microbial de-
terioration occurs within days; and off flavors and odors
developed, shortening the postharvest life with respect to
the intact fruit (Ahvenainen, 1996). All these changes im-
pact the fruit's phytochemicals compounds and its antiox-
idant capacity (Robles-Sanchez et al., 2007). It is crucial
to evaluate each processing step (sorting, washing, peeling,
cutting, treating, packing, cooling, transportation, storage)
(Fig. 18.3) with critical care to minimize damage and main-
tain quality and the product's postprocessing life.

Marbling
Marbling is caused by the acetic acid bacteria Acetobac-
ter peroxydans Visser't Hooft and Erwinia herbicola var.
ananas (Serrano) dye. Marbling disease has been reported
in essentially all pineapple production areas of the world
(Rohrbach, 1983). It is characterized by brown speckling
and abnormal hardening of the internal tissues (Rohrbach
and Apt, 1986). In contrast to pink disease, marbled-fruit
tissues can be discarded before being packed in the cans.
Potassium fertilization is an effective control method.

Yeast fermentation
This is caused by Saccharomyces spp. and is usually associ-
ated with overripe fruit, especially if mechanically injured.
The yeast enters the fruit through wounds. The skin turns
brown and leathery, and the fruit become spongy with bright
yellow flesh and is ruptured by large gas cavities. Losses
can be minimized by reducing sunburn and harvesting fruit
before they are overripe (Rohrbach and Johnson, 2003).

Fruit selection
Some quality problems of minimally processed pineapple
include browning, translucency, and juice leakage. Variety
and the maturity at harvest significantly influence ability to
minimally process the fruit. Marrero and Kader (2006) ob-
served that the low-acid hybrid 'Premium Select' cultivar
was less prone to leakage than the old 'Smooth Cayenne'
canning selection 'PRI 3620.' 'Spanish Red' pineapple
slices from riper fruit with 80-90% orange skin show
a higher rate of browning and consequently greater loss

Fruit fly quarantine
Quarantine treatments have been developed to disinfest
fruit for fruit flies and other insect pests before shipment.
The US Department of Agriculture (USDA) accepted that
pineapples with more than 50% 'Smooth Cayenne' in the
parentage are not a fruit fly host. Before this nonhost ruling