ANTI-NUTRITIONAL CONSTITUENT OF COLOCASIA ESCULENTA ...

Table AJ-4b: The phenolic compounds in the processed and unprocessed
Amadnmhe tuhers
Esikhawini white (EW)
Boiled white (BW)
Roasted white (RW)
Fried white (FW)
Esikhawini purple (EP)
Boiled purple (BP)
Roasted purple (RP)
Fried purple (FP)
Mtnbatnba white (MtW)
Mtnbatnba purple (MtP)
Makatini white (MakW)
Makatini purple (MakP)
Total phenols Tannjns Flavonoids
11.5 5.1 x 10- 0.03
7.1 (38) 8.1 x 10 (84) 0.009 (70)
10.0 (13) 1.7 x 10- (66) 0.01 (67)
10.8 (6) 1.9 x 10- (63) 0.014 (53)
13.0 1 x 10- 0.031
9.8 (24) 7.8 x 10 (22) 0.01 (68)
12.2 (6) 7.3 x 10 (27) 0.013 (58)
14.0 (0) 5.5 x 10 (45) 0.01 (68)
13.3 1 x 10- 0.034
11.9 4.2 x 10- 0.039
8.0
14.0 6.5 x 10-'
0.049
0.043
a Figures in parentheses indicate the percentage decrease over the values of the
corresponding raw tuber
The total phenol, tannin and flavonoid contents obtained in processed and unprocessed
Amadumbe tubers are given in Table A3-4b. Unprocessed tubers contained fairly low
levels of free phenolics and low levels of tannin. The reduction for total phenols was
highest during boiling, 38 per cent and 24 per cent for the white and purple Amadumbe
respectively.
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