2.5. Vitamin C determination
The concentration of vitamin C in banana was determined by a spectrophotometric method
. Ten grams of
banana was homogenized in about 100 ml of 4% w/w H2C2O
solution. The mixture was filtered in order to separate
the solid residue from the liquid. The liquid was then diluted to a certain volume with H42C2O
. For the calibration
process, the standard solutions were prepared from 100 ตg.ml-1
ascorbic acid solution in a certain volume of 4%
w/w H2C2O4
was added with 1 ml of 50 ตg.ml-1
CuSO4.5H
O solution (pH = 6). The absorbance values were
recorded at 249 nm.