Doe
Mon, Oct-28-02, 19:58
So since they are now producing genetically modified low
phytate (IP6/phytic acid) corn .. are there now going to be a
lot more ppisonings .. ?
3-10 Evaluation of the effect of phytic (inositol phosphate)
and linoleic acids on the biosynthesis of aflatoxin
S. SHAHID-ALI1, D. L. PARK2, and H. Njapau2. (1) Food Science
Department, Louisiana State University, 111-Food Science
Bldg., Baton Rouge, LA 70803, (2) Center for Food Safety &
Applied Nutrition, Food and Drug Administration (FDA), 200
C St. S.W., Washington D.C., DC 20204
Consumption of mycotoxins, especially aflatoxin B1 (AFB1), is
associated with occurrence of liver cancer. Naturally
aflatoxin contaminated corn extracts show a lower mutagenic
potential than pure AFB1 in the Salmonella/microsomal assay,
presumably due to the presence of inositol phosphates (InsPs)
and linoleic acid. The role of InsPs and linoleic acid on the
overall risk posed by AFB1 occurrence is important since they
comprise more than 1% of the dry weight of cereals, oilseeds
and nuts. This study was conducted to evaluate the effect of
the presence of InsP analogs and linoleic acid, on aflatoxin
production by Aspergillus flavus in Czapek-Dox liquid medium,
and on corn during storage. Czapek-Dox medium, containing
different phytic acid concentrations was inoculated with a
spore suspension of Aspergillus flavus and AFB1 production was
monitored by TLC during 25-days incubation at 28°C, in the
presence/absence of various ions. In the storage study, whole
kernel and cracked corn was also inoculated in the presence of
varying amounts of phytic and linoleic acids, in a controlled
environment for 5-weeks. Aflatoxin biosynthesis was monitored
every 4-days using HPLC. Inhibition of AFB1 biosynthesis in
liquid medium was observed as the concentration of InsP
increased. Complete inhibition of AFB1 production was recorded
at InsP levels of 0.5 and 1 mg/100ml in the absence of Fe++
and Zn++ ions. In storage, aflatoxin levels were ~50% lower in
samples separately treated with phytic and linoleic acids
after 14-days. Aflatoxin production in InsP-treated samples
was substantially lower than Linoleic acid-treated samples. No
such reductions were recorded in samples treated with
phytic-linoleic acids combination. Although individually
phytic and linoleic acids lower aflatoxin production, their
simultaneous presence negates this effect. These results do
not, however, reduce the benefits arising from reported
inhibition of aflatoxin mutagenicity/biosynthesis by the same
compounds.
Session 3, Toxicology & Safety Evaluation
8:30 AM - 12:00 PM, 2002-06-17
Who loves ya. Tom Jesus was a vegetarian!
http://jesuswasavegetarian.7h.com
Jesus was a vegetarian! http://www.nucleus.com/watchman Moses
was a mystic! http://www.nucleus.com/watchman/light.html
phytate (IP6/phytic acid) corn .. are there now going to be a
lot more ppisonings .. ?
3-10 Evaluation of the effect of phytic (inositol phosphate)
and linoleic acids on the biosynthesis of aflatoxin
S. SHAHID-ALI1, D. L. PARK2, and H. Njapau2. (1) Food Science
Department, Louisiana State University, 111-Food Science
Bldg., Baton Rouge, LA 70803, (2) Center for Food Safety &
Applied Nutrition, Food and Drug Administration (FDA), 200
C St. S.W., Washington D.C., DC 20204
Consumption of mycotoxins, especially aflatoxin B1 (AFB1), is
associated with occurrence of liver cancer. Naturally
aflatoxin contaminated corn extracts show a lower mutagenic
potential than pure AFB1 in the Salmonella/microsomal assay,
presumably due to the presence of inositol phosphates (InsPs)
and linoleic acid. The role of InsPs and linoleic acid on the
overall risk posed by AFB1 occurrence is important since they
comprise more than 1% of the dry weight of cereals, oilseeds
and nuts. This study was conducted to evaluate the effect of
the presence of InsP analogs and linoleic acid, on aflatoxin
production by Aspergillus flavus in Czapek-Dox liquid medium,
and on corn during storage. Czapek-Dox medium, containing
different phytic acid concentrations was inoculated with a
spore suspension of Aspergillus flavus and AFB1 production was
monitored by TLC during 25-days incubation at 28°C, in the
presence/absence of various ions. In the storage study, whole
kernel and cracked corn was also inoculated in the presence of
varying amounts of phytic and linoleic acids, in a controlled
environment for 5-weeks. Aflatoxin biosynthesis was monitored
every 4-days using HPLC. Inhibition of AFB1 biosynthesis in
liquid medium was observed as the concentration of InsP
increased. Complete inhibition of AFB1 production was recorded
at InsP levels of 0.5 and 1 mg/100ml in the absence of Fe++
and Zn++ ions. In storage, aflatoxin levels were ~50% lower in
samples separately treated with phytic and linoleic acids
after 14-days. Aflatoxin production in InsP-treated samples
was substantially lower than Linoleic acid-treated samples. No
such reductions were recorded in samples treated with
phytic-linoleic acids combination. Although individually
phytic and linoleic acids lower aflatoxin production, their
simultaneous presence negates this effect. These results do
not, however, reduce the benefits arising from reported
inhibition of aflatoxin mutagenicity/biosynthesis by the same
compounds.
Session 3, Toxicology & Safety Evaluation
8:30 AM - 12:00 PM, 2002-06-17
Who loves ya. Tom Jesus was a vegetarian!
http://jesuswasavegetarian.7h.com
Jesus was a vegetarian! http://www.nucleus.com/watchman Moses
was a mystic! http://www.nucleus.com/watchman/light.html