This method describes how to determine not only the variety of barley but whether a lot of barley consists of a mix of varieties.
Barley intended for malt production as well as barley malt
Separation and identification of the protein (hordein) fraction of barley or barley malt by means of gel electrophoresis. The method is suitable for all types of barley, as long as reference substances are available. However, the method cannot be used to identify barley varieties used to produce malt that has been so strongly modified that the protein fraction is almost completely degraded.
Malt intended for use in beer brewing or elsewhere in the food industry
Using a buffer solution, malt extract is produced, and then under defined conditions the extract is incubated on an azo-barley glucan substrate. The substrate is coupled with an azo dye, which is degraded by the β-glucanase activity to form low-molecular weight fragments. After addition of the precipitating agent, these fragments stay in solution and can be spectrophotometrically determined in the supernatant after centrifugation. The absorbance in the supernatant depends directly upon the activity of the β-glucanase in the analyzed malt.
This method describes how to determine malted barley varieties and how to detect mixtures of different barley varieties in one lot of malt.
Malt intended for use in beer brewing or elsewhere in the food industry
Barley intended for the production of malt is to be evaluated on the basis of the characteristics described below.
visual assessment
This method describes how to determine whether kernels are cracked as part of the visual and manual inspection of a lot of barley.
Barley intended for the production of malt is to be evaluated on the basis of the characteristics described below.
Visual assessment
The method provides an estimate of the portion of pre-germinated barley grains at the time of harvest or prior to storage in silos.
Barley intended for the production of malt is evaluated with regard to pre-germination.
The onset of germination is accompanied by the synthesis of enzymes, which can be made visible using fluorescein dibutyrate (FDB). The reagent fluoresces in the presence of lipases.
In order to make the enzyme activity visible, the kernels are first split in half and coated with the FDB reagent after which they are examined in a suitable measuring device under UV light. An intense yellow fluorescence can be seen in the parts of the kernels where enzyme activity is present.