Define the Qualitative Technique in Nutritional Biochemistry?
In this manual you will be familiarized with simple qualitative techniques and tests to identify compounds such as carbohydrates, in the laboratory. The objective of qualitative analysis is the identification of the constituents of a substance, or mixtures of substances or of solutions and the manner in which the component elements or groups of elements are combined with one another. It does not involve determining relative proportions of these elements. Most of the tests are based on properties of the compound/substance being studied.
Several qualitative tests have been devised to detect compounds. These tests utilize a test reagent that will yield a colour change after reacting with specific functional groups of the compounds being tested. You would realize that these tests range in specificity from the very general (i.e. Molisch test for carbohydrates) to the very specific (i.e. mucic acid test for galactose). However, if you were asked to estimate the quantity of a monosaccharide, disaccharide or polysaccharide present in a given solution, you would not be able to do so because for this you need to understand quantitative analysis. Let us then get to know about quantitative analysis.