Enzymatic analysis of Food with reagents from DiaSys

Principle of enzymatic analysis

Constituents of food, cosmetics, and pharmaceuticals could be determined fast, with high accuracy and sensitivity by the use of enzymes. Thereby the analyte (the substrate) is converted in the reaction mixture by the enzymes in the reagent.

Principle of enzymatic reactions:
Substrate + Coenzyme --- Enzyme ---> Product + Coenzyme’

Substrate determinations in food analysis are normally carried out as end points in the enzyme-catalysed reactions. The substrate which has to be measured is transformed quantitatively and one of the reaction products is measured photometrically. This means that the total determination time is not dependent on the working time needed for pipetting and absorption measurements but only on the incubation period until the reaction has reached end point.

The major advantage of enzymes in analysis is their ability to react specifically and stochiometrically with an individual component of a sample. Other ingredients of the samples and additives such as antioxidants, or preservatives do not react. This avoids lengthy separations of the components and reduces the time and labour needed for analysis.


Measurement principle

The enzymatic assay is measured spectrophotometrically. The measurement based on the formation or consumption of NADH or NADPH. These measurements usually occur without interference since the corresponding extinction coefficients are almost independent of the reaction conditions and also they are very well known.
If spectral photometers are used, the measurements of the concentration of NADH or NADPH is done at the maximum absorption of light (340 nm).
In some cases, the NAD/NADH-system cannot be used or is only of limited use for the determination due to reaction equilibrium. In these cases, the NAD/NADH reaction is combined with a colorimetric reaction. The NADH formed reduces iodonitrotetrazolium chloride (INT) to a formazan dye which is measured.


Enzymatic analysis of food with reagents from DiaSys

Founded in 1991 DiaSys is a company focusing in the development and manufacture of high-quality ready-to-use reagents for Clinical Chemistry Tests. With more than 130 employees at Holzheim near Limburg (Germany), DiaSys manufactures liquid and stable reagents for customers in more than 80 countries worldwide.
DiaSys modernize the enzymatic analysis of food by the transfer and adaptation of their knowledge in development of liquid and stable test-kits. Using innovative research, development and manufacturing techniques DiaSys produces the highest quality, liquid stable ready to use reagents for enzymatic food analysis.

The benefits of DiaSys reagents

 -  Ease of use:
No errors and no time wasted in reconstitution by using the liquid and ready to use reagents. Furthermore the pipetting steps are minimized by the use of 2 or maximum 3 reagents per assay. The pipetting order is user friendly by standardization on a 4+1 or 4+1+1 format.

 -  Stable:
Due to the liquid and stable form the reagents are always available when needed and can be used up to the very last drop, even after opening.

 -  Cost-efficient by automation:
All tests are developed for manual use on photometers and fully automated systems, e.g. Respons, Konelab, Vitalab, Hitachi, LISA etc.
 

More information about Enzymatic analysis - foodanalysis@diasys.de