Overall chemical reaction of carbohydrate’s hydroxyl group. In
presence of concentrated acids, i.e., sulfuric acid, the monosaccharides (aldose
or ketose) get dehydrated to form furfural compounds. These products are
then able to react with phenol such as naphthol and anthrone to yield a
colourful product.
For laboratory purpose, it is advisable to perform these tests with the
individual rather than mixture of sugars. Use of sugar solutions of different
concentrations (0.1 – 1%) during these experiments would also provide a
valuable data regarding the test’s sensitivity. Some examples of these rapid
tests are summarised in Table