Determination and comparison of ascorbic acid contents in selected fruits and vegetables obtained from Ilorin Metropolis
The ascorbic acid contents of eight different fruits and four vegetable types were determined by iodometric titration method using standardized sodium thiosulphate against ascorbic acid in the fruit and vegetable extracts. A blank titration was first carried out on the thiosulphate only followed by titration with the extracts. From the blank titre, the total amount of water-soluble iodine produced in the reaction was calculated while the amount of water-soluble iodine that reacted with the sample was obtained from the test titre. The quantity of ascorbic acid in milligrams, present in each fruit and vegetable sample was obtained by calculations. The results showed that the amount of ascorbic acid in the selected fruits was in the order of Orange > Tangerine > Water melon > Pineapple > Grape > Apple > Lemon > Lime and the vegetables, in the order of Pumpkin > Bitter leaf > Water leaf > Amaranth leaf.
Keywords: Ascorbic acid, Fruits, Iodometry, Vegetables, Water-soluble Iodine