144
13
rg
% saponin = wt of saponin / wt of sample x 100
Determination of cyanogenic glycosides
Cyanogenic glycosides was determined using the method
described by AOAC [12].
Exactly 1.0g of sample was
weighted in 250cm3
volumetric flask, 200cm3
of distilled
water was added to it and this was allowed to stand for
2hrs. Distillation was done until 160ml of distillate was
obtained. This distillate was collected in a 250cm3
conical
flask containing 20cm3
of 2.5% NaOH. To the distillate that
contains cyanogenic glycosides, 8cm3
of 6M ammonium
hydroxide and 2cm3
of 5%KI was added. The mixture was
titrated with 0.02M silver nitrate against a black
background. Permanent turbidity shows the endpoint.
Cyanogenic glycoside content (mg/100g) Titre volume
/Aliguot volume x extract volume / sample weight x 100
Determination of Tannin.
This was determined using the method described by AOAC
[12].
Exactly 1.0g of the sample was weighed into a conical
flask and 50cm3
of water was added to it. It was then
allowed to stand for 1hr and filtered into 50cm3
volumetric
flask. The filter paper was rinsed with distilled water and the
extract diluted to 100cm3
. 2.5cm3
of the diluted extract was
measured into 50ml flask followed by the addition of 1cm3