Message-ID: <12602.000115@acnet.net> Date: Sat, 15 Jan 2000 14:27:23 -0600 From: Douglas Hinds <mailto:dmhinds@acnet.net> Subject: Re: Calcium carbide for ripening fruit To: mailto:DEVEL-L@LISTSERV.AMERICAN.EDU
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Donald,
Saturday, January 15, 2000, 4:07:09 AM, you wrote (starting from the
end):
DZO> How common is this practice elsewhere?
Very.
DZO> Does anyone know of more definitive info on the health aspects?
I avoid it. I neither buy it nor eat food it's been used on, and I can
usually tell by both the appearance and origin of the fruit. However,
many common fruits (i.e. bananas and oranges) and vegetables (i.e.
tomatoes, which are botanically fruits) are routinely picked green and
force ripened or force ripened on the plant a few days before picking
(i.e. pineapple) using supposedly equivalent synthetic substances such
as 2-chlorethelphosphonic acid (which liberates ethylene) in the U.S.
In other words, the great majority of people in the U.S. have never
eaten a naturally ripened banana, pineapple, mango or orange (or for
that matter, fruit from a tree on it's own roots).
I suggest you buy directly from growers who neither use it nor lie
about it, or distributors that will set aside green fruit for you
before "ripening" that was harvested sufficiently close to maturity.
If needed you can hasten the ripening process by lining a cardboard
apple box (or equivalent) with newspaper all around (the number of
sheets required depends on the temperature - use 3 for colder
weather), placing the green fruit in it along with a small amount of
riper fruit, folding the newspaper over it and letting the naturally
emitted ethylene accumulate.
Acetylene, the end product of Calcium Carbide + water (C2Ca + H2 O >
CaCO3 + C2H2) provokes the same effects as the fito-hormone ethylene
(CH2), but neither Calcium Carbide nor synthetic ethylene when used to
"ripen" less mature fruit, produce results that approach those of
fruit picked closer to it's peak. The difference in toxicity between
C2H2 + CaCO3 and CH2 may be what you're after, while I'm focusing on
generalized industry practices that go beyond the lesser developed
countries where calcium carbide use is more prevalent.
I have exported fruit on a commercial scale (pilot project) of a type
normally force ripened, that was instead picked close to it's peak and
while special (different) handling procedures are required and
handling costs are increased slightly, quality is enhanced to the
degree that both consumers and supermarkets will gladly pay
significantly more than the cost of the special handling procedures,
which increased costs only slightly.
Incidentally, both calcium carbide and synthetic ethylene are commonly
used to force flowering, also; while other hormones are commonly used
to retard both flowering and the ripening process in order to lengthen
the growing season, program harvesting for periods when product is
scarce and expensive, and / or produce larger fruit.
Unfortunately, most people don't know what they're eating and when
these issues *are* raised, the industry's communications pros will
assure all that all is well ("the finest and safest food in the
world"), go back to sleep and don't listen to the "cranks and
radicals" (just keep the cash coming). Governments often protect their
industries (the U.S. ECM conflict over GMOs is centered on the proper
role of government - protect establish industry or protect public
health from possible health threats. Where the benefit of the doubt
should reside is what's in question).
The results of forced flowering appear to be less severe that those of
forced (accelerated) ripening, since a plant whose flowering is forced
will NOT respond - meaning that in spite of the application, it won't
flower unless the conditions it requires are otherwise adequate and if
so, the flowering process is then complete; whereas when used to
hasten ripening, ripening is only simulated - a ripe appearance is
produced but internal quality is almost always significantly lower and
the decomposition process is also accelerated. Also, substances used
at the outset of the fruits development are less likely to be present
in the fruit than those used shortly before or after harvest.
Note than one practice is used (rarely) by farmers, while the other is
generally done by distributors, except when a given product's quality
severely deteriorates in a noticeable way when ripening is forced
after harvest and instead is done in the field. And this often is done
at the request of those distributors marketing the product. For some
fruits this is a generalized practice and after the end of the pilot
project, our growers went back to it due to pressure from distributors
who were farther from consumers than the more direct channels I used.
(However, there will be a sequel to this that is yet to occur).
DZO> For a number of years, some fruit vendors in West Africa have
DZO> used calcium carbide to ripen immature fruits for sale. This
DZO> permits the growers to harvest before maturity to get money
DZO> sooner (sometimes the growers are the ones using the carbide,
DZO> sometimes the retailers who buy the fruit - as I understand it).
Harvesting green also facilitates handling, so that the boxes or
crates can be literally thrown around (and I'm referring to manual
handling practice in the U.S., although most produce is handled there
using forklifts).
DZO> ... some people try to avoid it. But as far as I know, such
DZO> market pressures have not been a disincentive to contunued use of
DZO> the practice.
There is not enough naturally ripened product out there to make much
of a real difference, and those that do provide it have neither
systematized their handling procedures nor developed an adequate
infrastructure and generally lack the volumes required to justify that
expense. This is where organizational work and research come in. And
this is what we do.
Once again, I haven't gone into the toxic mechanisms here at any great
length (but you wouldn't want to close yourself up very long in a
chamber sealed for calcium carbide ripening), presenting instead an
overview of why it happens and what can (and needs to) be done.
Douglas Hinds - CeDeCoR, A.C.
Centro para el Desarrollo Comunitario y Rural, Asociacion Civil
(Center for Rural and Community Development, a Mexican non-profit organization)
Cordoba, Veracruz; Cd. Guzman, Jalisco & Reynosa, Tamaulipas Mexico
mailto:dmhinds@acnet.net, cedecor@acnet.net,
mailto:cedecor@ipnet.com.mx, dhinds@prodigy.net.mx
*********** REPLY SEPARATOR ***********
DZO> For a number of years, some fruit vendors in West Africa have
DZO> used calcium carbide to ripen immature fruits for sale. This
DZO> permits the growers to harvest before maturity to get money
DZO> sooner (sometimes the growers are the ones using the carbide,
DZO> sometimes the retailers who buy the fruit - as I understand it).
DZO> I learned of this process a decade and a half ago, but just
DZO> recently read about it again in one of the papers here in Bamako
DZO> ("Le Malien" 30 Dec. 99). The article says that the health
DZO> effects are not yet known, although some people claim to have
DZO> suffered stomach upset, diarrhea, and even allergic type
DZO> reactions from fruit so treated. The recommendation (a good idea
DZO> in any case these days) is to wash the fruit well and not to
DZO> consume the skin (which is sometimes done with mangos).
DZO> The fruit is wrapped up and moistened calcium carbide is placed
DZO> over it; the whole package kept in a closed space. The chemical
DZO> emits heat and acetylene which hasten the ripening of the fruit.
DZO> It is usually fairly easy to identify such fruit, and some people
DZO> try to avoid it. But as far as I know, such market pressures have
DZO> not been a disincentive to contunued use of the practice.
DZO> --
DZO> Don Osborn mailto:osborndo@pilot.msu.edu
DZO> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
DZO> "A superficial culture, unsupported by a cultivated morality, is
DZO> as `a confused medley of dreams.'" `Abdu'l-Baha (1876)
DZO> "The rise and fall of images of the future precedes or accompanies
DZO> the rise and fall of cultures." Frederick Polak (1960)
DZO> "Les sociétés occidentales ne se voient plus clairement dans le
DZO> miroir du futur; ...." Ignacio Ramonet (1998)
DZO> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
DZO> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
DZO> "Where there is no vision, the people perish." Proverbs 29:18
DZO> "Let your vision be world-embracing . . . " Baha'u'llah
DZO> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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