Devices for vitreousness determination

Grain glassiness is a trait that characterizes the structure of the endosperm of the grain (consistency). Glassiness indirectly indicates the protein or starch content of the grain.
Depending on the vitreousness of the grain, different techniques of preparation of wheat for varietal milling are used and the modes of milling process are established.
Grain vitreousness is determined by grain section with external inspection of slices and with the help of a diaphanoscope.
To determine the vitreousness, 100 whole grains are extracted from the clean grains that remain after the definition of contamination without selection. Each of them is cut with a razor blade across (in the middle) and depending on the consistency of the cut, it is referred to the group: vitreous, partially vitreous or floury.
Total vitreousness is expressed as a percentage of 100 grains.
When calculating the percentage of total vitreousness, half the number of partially vitreous grains is added to the number of fully vitreous grains to get the total vitreousness of the grain sample.
When you use a diaphanograph to determine the vitreousness, you put 50 grains (out of 100 grains that you have previously extracted) with the groove down on a grid with oval holes so that there are no gaps between the grains and the holes. The grid with grains is inserted into the slit of the device body. The light source is a 55 W electric lamp installed at the bottom of the device, under the grid. Between the light source and the grid there is a frosted glass, which scatters the light.
For better recognition of grains in the device (above the grid) there is a magnifying glass. There is a device for focusing the image.
When viewing the grains, the number of glassy and floury grains is counted. Vitreous grains are transparent, well translucent; floury grains are dark, not translucent; partially vitreous grains are translucent.
Also determine in another portion of grains (also 50 grains). The results of counting in each portion are summed up. The results of the determination of vitreousness, put with an accuracy of 1.0%.
Discrepancies between two parallel determinations of the total vitreousness of wheat, allowed not more than 5%