ANTI-NUTRITIONAL CONSTITUENT OF COLOCASIA ESCULENTA ...

water. The homogenate was filtered and the filter residue was then washed with 75 ml of
methanol-chloroform (2:1, v/v). The filtrates were combined in the separating funnel with
125 ml ofchloroform and 145 ml ofwater and phases allowed to separate. The chloroform
layer was then collected and diluted with benzene and concentrated in vacuo. The residual
lipids were immediately dissolved in 25 ml ofchloroform-methanol (1:1, v/v) mixture.
B.A.I.S.4.2 Hexane extraction
B.A.I.S.4.3 Iodine value
15 g of dried Amadumbe was dissolved in 90 ml of hexane. The mixture was stirred
occasionally for 15 minutes. Solid particles were filtered using rough filter paper and the
extract was filtered again using fine filter paper with 0.45 lIlI1 pores. Hexane was
evaporated at room temperature to yield the plant oil.
5 mg lipid was dissolved in 5 ml chloroform and to this solution 5 ml ofDaIn's reagent was
added in a 50 ml Erleumeyer flask. The solution was mixed and left at room temperature in
the dark for 15 minutes. 0.5 ml ofpotassium iodide was added to this mixture with 0.5 ml
of water and few drops of starch indicator. A standard thiosulfate solution was used to
titrate the liberated iodine to the endpoint colour ofmilky. A blank was titrated containing 5
ml ofchloroform only.
B.A.I.S.4.4 Column Chromatography
20 g of silicic acid was preheated in the oven at 120°C. A slurry of the gel was then
prepared with 35 ml chloroform in a beaker and poured into a 48x2.l5 cm chromatography
tube,the stopcock was openend slowly to dislodge the air bubbles which result in settling of
the column. The solvent level was allowed to drop to the top of silicic acid; the bed was
washedwith 2 column volumes of 35 ml chloroform. The Amadumbe exract was added in
the column at the top ofthe solvent and the elution ofthe column was done at the flow rate
of3 ml/min with
175 ml chloroform., 10 column volumes, 40 column volumes with 700 ml acetone and 10
column volumes with 175 ml methanoL
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