The Wheat Quality Laboratory of Small Grain Institute performs several analyses on wheat grain and/or flour.
Table 1. Complete list of analyses performed, including prices
Test weight, also known as hectolitre mass, is a measure of the volume of grain per unit. It is usually expressed as kilograms per hectoliter and is a good indication of grain-soundness. Millers usually use test weight as an indication of expected flour yield. To perform this analysis, 1kg clean seed is required.
This analysis is performed to determine whether wheat kernels are red or white. In South Africa only red wheat breeding lines are allowed to be submitted for bread wheat cultivar classification. A hundred kernels are required for this analysis.
A mixogram is obtained from a Mixograph after water and flour has been mixed for e.g. six minutes.The mixogram will reach a peak (peak time), which is of great importance to bakers. The amount of flour and water required is dependant on the protein and moisture content of the specific flour sample. Mixograph models available uses more or less 10g or 35g of white flour.
A farinogram is obtained from a Farinograph and it gives us information on the flour's water absorbing capacity, the dough's stability and development time. Water absorption is an important characteristic for bakers. To perform this analysis, 600g of white flour is required.
The Mixolab supplies us with information regarding protein, starch and enzyme in one single analyses.
6. SDS-sedimentation volume
SDS-sedimentation volume is basically a measurement of a sediment volume of a wheat-flour suspension after it has been acidified. It is used as an indicator of wheat quality, but unfortunately it cannot distinguish between strong and over-strong flour quality. Five grams of flour is required to perform this analysis.
7. Protein content
Flour protein content influences the functionality of wheat and it can range between 6% and 25%. About 10g of flour is required to perform this analysis.
8. Falling number
This test is an indirect measurement of α-amylase activity in samples to determine if samples contain sprouted grain, though not always visibly sprouted. Flour from sprouted grain is undesirable for bakers, because it results in undesirable loaf characteristics.
9. Flour yield
Flour yield or flour extraction is the percentage of flour that can be obtained from a given amount of wheat. Flour yield is a very important bread wheat quality parameter, because millers make more profit from cultivars that deliver more flour from a given amount of wheat. The Junior Quadrumat mill is used for flour yield determination on smaller grain samples (50g to 250g). For flour yield determination on the Bühler mill, 500g of grain is required. If other analyses are also required on this flour, 1,5kg of grain is required.
10. Loaf volume
Baking quality is evaluated by the ability of the flour to produce large, well-shaped loaves and by the water absorbing-capacity of the flour. The mass of flour needed for this analysis, depends on the moisture content of the flour, thus more or less 100g of flour is needed.
11. Gluten content
Wet gluten is obtained when a flour sample is washed with a sodium chloride solution – the starch and all other soluble components are removed and only the gluten part is left. Ten grams of flour is required to perform this analysis.