Washington, DC
November 29, 2007
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Orange-fleshed honeydew melons may be a
better choice for organic growers than
cantaloupe because of the honey dew’s absence of
netting, which is known to harbor bacteria that
can cause human illness.
Photo by Peggy Greb. |
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Among the various
foods associated with foodborne illness, cantaloupes—or
muskmelons—have been implicated in more than 25,000 individual
cases in the United States since 1990.
The problem lies
in cantaloupes’ rough outer netting, which is known to harbor
human-illness pathogens and defy sanitation measures. Microbes
can hide in the netting’s crevices, covered by naturally forming
biofilms that protect them from sanitizers. When netted melons
are cut, any microbes present on the exterior can be transferred
to the inner flesh.
For organic melon
growers—who use manure as fertilizer—this is a major concern.
The organic melon market is a relatively new one, but at its
forefront are
ARS scientists searching for new ways to solve this
food-safety problem.
Plant physiologist
Gene Lester, in the Crop Quality and Fruit Insects Research Unit
at Weslaco, Texas, leads a team of ARS scientists developing
ways to reduce foodborne illness associated with cantaloupe.
They suggest that netted cantaloupes be replaced with nonnetted
melon genotypes, such as an orange-fleshed honeydew (Cucumis
melo, Inodorus group). This kind of melon is a cross between a
cantaloupe and a honeydew. The smooth-skinned honeydew types
don’t carry the same consumer risk as melons with rough outer
netting.
Another benefit of
these melons is their nutrient content. Until recently, little
has been known about how the health-promoting phytochemicals or
antioxidant capacity of orange-fleshed honeydews compare to
those of netted cantaloupes. Lester’s collaborations have shown
that orange-fleshed melons contain higher amounts of vitamins
(C, A, and folic acid), minerals (calcium, iron, magnesium, and
potassium), and antioxidants (phenolics and enzymes).
Current work with
Earl Harrison, chair of human nutrition at Ohio State
University-Columbus and former research leader of the ARS
Phytonutrients Laboratory in Beltsville, Maryland, is comparing
the beta-carotene in cantaloupes and orange-fleshed honeydews to
that in carrots and sweetpotatoes. It is expected that the
beta-carotene in fruit—particularly warm-season fruit like
melons—will be better absorbed, or more bioavailable, than that
in vegetable crops. Melons may equal carrots when it comes to
exceeding the recommended daily amounts of beta-carotene.
“Orange-fleshed
honeydews could easily be marketed as specialty produce in
retail supermarkets,” says Lester. “That’s where their superior
sweetness, color, taste, and nutritional levels could be
capitalized on.” The melons store well, too—around 3 weeks,
compared to 10 to 14 days for a typical netted cantaloupe in
simulated commercial retail storage.
One cultivar,
Orange Dew, is being grown organically in limited quantities in
the United States. It has already won out in a taste test with
the netted Cruiser cantaloupe because it is sweeter. Orange Dew
has a Brix—a measurement of sweetness—of 11 to 14, compared to 9
for most cantaloupes. Sweetness has been shown to be the most
important taste factor in repeat purchase of melons.
By
Alfredo Flores, Agricultural Research Service Information
Staff.
This research
is part of Quality and Utilization of Agricultural Products, an
ARS national program (#306) described on the World Wide Web at
www.nps.ars.usda.gov.
Gene E. Lester
is in the USDA-ARS
Crop Quality and Fruit Insects Research Unit, 2413 E.
Highway 83, Weslaco, TX 78596; phone (956) 447-6322, fax (956)
447-6345.
Científicos evalúan melones dulces orgánicos con pulpa de color
naranja
Un grupo de científicos del Servicio de Investigación Agrícola
(ARS) ha evaluado los méritos de algunos melones que combinan
los mejores atributos del cantalupo y el melón dulce.
El grupo ha buscado nuevas maneras para resolver la preocupación
principal de los cultivadores de los melones tanto orgánicos
como convencionales: la seguridad alimentaria, según el
fisiólogo de plantas Gene Lester en la Unidad de Investigación
de Calidad de Cultivos e Insectos de Fruta, mantenida por ARS en
Weslaco, Texas.
Los cantalupos, también conocidos como 'muskmelons' en inglés, a
veces han probado positivos para la presencia de las bacterias
Salmonella lignieres y Escherichia coli O157:H7. Esto resulta de
la capacidad de los microbios perjudiciales para esconderse en
la cáscara áspera de la fruta y de este modo escaparse de
medidas de sanidad.
Cuando los melones se cortan, los microbios
perjudiciales--escondiéndose en grietas en la cáscara y
cubiertos con biocapas que forman naturalmente y los protegen
contra desinfectantes--pueden ser transferidos a la pulpa
interior.
Los investigadores compararon los cantalupos que tienen una
superficie áspera--el tipo de melón con pulpa de color naranja y
una corteza de color verde oscuro--con un genotipo de melón que
ofrece niveles altos de fitonutrientes y una superficie lisa.
Ellos descubrieron que los melones con la superficie lisa tienen
menos probabilidad de esconder las bacterias.
Los investigadores también están evaluando el sabor de los
melones lisos. Un tal melón, llamado 'Orange Dew', está siendo
cultivado orgánicamente en cantidades limitadas en EE.UU. En
pruebas de sabor, 'Orange Dew' recibió una calificación más alta
de la del cantalupo tradicional 'Cruiser'. Esto es porque
'Orange Dew' tiene un valor Brix--una medida de dulzor--de 11 a
14, comparado con un valor Brix de 9 para la mayoría de
cantalupos. El dulzor es el factor más importante de sabor en
las compras repetidas de melones.
Los melones dulces con pulpa de color naranja también se
almacenan bien--hasta aproximadamente tres semanas, comparados
con 10 a 14 días para el cantalupo típico en condiciones
simuladas de almacenamiento comercial.
Lea más sobre la investigación en la revista 'Agricultural
Research' de noviembre/diciembre del 2007:
http://www.ars.usda.gov/is/AR/archive/nov07/honeydew1107.htm
ARS es la agencia principal de investigaciones científicas
del Departamento de Agricultura de EE.UU. |
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