2.5. Vitamin C determination
The concentration of vitamin C in banana was determined by a spectrophotometric method14, 15. Ten grams of banana was homogenized in about 100 ml of 4% w/w H2C2O4 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 H2C2O4. For the calibration process, the standard solutions were prepared from 100 μg.ml-1 ascorbic acid solution in a certain volume of 4% w/w H2C2O4 was added with 1 ml of 50 μg.ml-1 CuSO4.5H2O solution (pH = 6). The absorbance values were recorded at 249 nm.