Enzymatic analysis consists in the determination of certain substances by the use of enzymes, which can be seen as reagents for specific catalysis of biochemical reactions. Enzymatic analysis is therefore a special form of chemical analysis. Enzymes are the most specific reagents known and therefore the results obtained are the most accurate ones. Enzymes react only with their substrates. Other ingredients of the sample and additives such as antioxidants or preservatives do not react.
Enzymatic determination of substrates are carried out to determine with precision and accuracy food ingredients and to control any change that might have occurred during processing and storage. Chemical methods are not always suitable because they are not always specific enough.
Enzymatic determination of substrates are further used for measuring metabolic end products of microorganisms in order to make an assessment regarding the sterility of the sample. These substrates determinations are usually very quick, requiring only a few minutes, while the classical microbiological count methods need one or two days. Another advantage is that a germ count is senseless after, for example, a heat treatment process but the substrates for these special enzymes remain unchanged.
Interactions between sample ingredients do not occur during enzymatic analysis due to the very gentle reaction conditions so that no matrix effects occur.
Enzymatic analysis also includes measurements of enzymatic activities. They are made for:
Enzymatic determinations can be carried out in short time but a distinction is to be made between the actual working time and the waiting period. Furthermore, the time factor should not be evaluated from other features but closely connected with:
The enzymatic analysis fulfils all requirements regarding safety and environmental protection. There are no disposal problem because biochemical reagents are not dangerous.
The enzymatic determination of substrates is limited either when no enzymes are known in nature to transform a certain substrate, or when it is not possible to follow the enzymatic reaction due to insufficient measuring techniques. These limitations can be overcame combining enzymatic methodology with immunological methods. There are antibodies for all chemical defined compounds, even for those which do not occur naturally. If enzymes are used as marker substances the range of application for enzymatic analysis is broadened widely, being practically unlimited.
With these techniques, compounds such as low molecular toxins in food, drug residues or compounds of high molecular weight such as proteins can be determined.