Biochemical and Histopathological Effects of Aflatoxin on ...

methods for primary extraction, the solvent system <strong>of</strong>acetone: water (70:30
or 65:35) to extract toxin from cottonseed, peanuts <strong>and</strong> other agricultural
commodities, as suggested by Pons et al. 1966a or Stol<strong>of</strong>f et al.1966, is
advantageous because neutral <strong>and</strong> polar lipids are relatively less soluble in
acetone-water mixture <strong>and</strong> their interference during subsequent analytical
steps, is thus avoided. Hence efficient defatting <strong>and</strong> aflatoxin extraction are
conducted simultaneously. The presence <strong>of</strong> some water appears to facilitate
removal <strong>of</strong> aflatoxin or the release <strong>of</strong> aflatoxin into the extracting solvent
(Goldblatt,1971). Later, Pons et al.1980 modified the solvent system to
85:15 ratio <strong>of</strong> acetone: water in which neutral <strong>and</strong> polar lipids are not
soluble. Hence in the present study, Pons modified solvent system <strong>of</strong> 85:15
ratio <strong>of</strong> acetone: water was used as the ideal solvent system believed to
selectively extract aflatoxin.
As it was believed that a certain amount <strong>of</strong> moisture could facilitate
the growth <strong>of</strong>the fungus <strong>and</strong> therefore the extraction <strong>of</strong>aflatoxin from it, in
the present study, rice grain was prewetted with 10 ml <strong>of</strong> Czapek's
concentrate instead <strong>of</strong> water. As supporting evidence it was reported that
Lee, 1965 slurried defatted peanuts <strong>and</strong> peanut meal with tenfold excess
water <strong>and</strong> extracted with chlor<strong>of</strong>orm by shaking for 30 min on a shaker. The
advantage <strong>of</strong> prewetting the materials as reported by Lee was that almost
pure aflatoxin extract could be obtained <strong>and</strong> hence this was adopted as the
<strong>of</strong>ficialmethod for the extraction <strong>of</strong>aflatoxin.
Precipitation <strong>of</strong> interfering substances, such as pigments, lipids <strong>and</strong>
fatty acids can also be achieved using clarifying agents, such as lead acetate
<strong>and</strong> in this study also a 20% lead acetate solution was used to precipitate the
interferingsubstances.
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