acute toxicity not been met, but
also, no demonstration of chronic safety has been made.
The fact that methyl alcohol appears in other natural
food products increases greatly the danger of chronic
toxicity developing by adding another unnatural source
of this dangerous cumulative toxin to the food system.
NATURAL SOURCES OF METHANOL
Methanol does appear in nature.
To determine what impact the addition of a toxin
will have on an environment it is very helpful to
accurately determine the background levels of consumption.
Fruit and vegetables contain pectin with variable
methyl ester content. However, the human has no digestive
enzymes for pectin, particularly the pectin esterase
required for its hydrolysis to methanol. Fermentation
in the gut may cause disappearance of pectin but the
production of free methanol is not guaranteed by fermentation
In fact, bacteria in the colon probably reduce methanol
directly to formic acid or carbon dioxide (aspartame
is completely absorbed before reaching the colon).
Heating of pectins has been shown to cause virtually
no demethoxylation: even temperatures of 120 C produced
only traces of methanol. Methanol evolved during cooking
of high pectin foods7 has been accounted for in the
volatile fraction during boiling and is quickly lost
to the atmosphere. Entrapment of these volatiles probably
accounts for the elevation in methanol levels of certain
fruit and vegetable products during canning.
In the recent denial by the food and drug Administration
of my request for a public hearing on this issue,
the claim is made by them that methanol occurs in
fruit juice at an average of 140 parts per million
(a range of between 15-640 parts per million). This
often used average originates from a informative table
in a conference paper presented by Francot and Geoffroy.
The authors explain that the data presented in the
table "may not" represent their work but
"other authors". There is no methodology
given nor is the original source cited and only the
identity of the lowest methanol source, grape juice
(12 ppm), and the highest, black currant (680 ppm),
are revealed. The other 22 samples used to generate
this disarmingly high average are left completely
to the imagination. The authors conclude their paper
by insisting that "the content of methanol in
fermented or non-fermented beverages should not be
of concern to the fields of human physiology and public
health." They imply that wines "do not present
any toxicity" due to the presence of certain
natural protective substances. When they present their
original data relating to the methanol content of
French wines (range 14-265 ppm) or when the methanol
content of any alcoholic beverage is given, the ratio
of methanol to ethanol is also presented. Of the wines
they tested, the ratio associated with the highest
methanol content (265 ppm) indicates over 262 times
as much ethanol present as methanol. the scientific
literature indicates that a fair estimate of methanol
content of commonly consumed fruit juices is on the
order of 40 parts per million (Table 1). Stegink,
et al.
