The moisture content of a milled product is an important part of analysis, as its result is used in other tests. Moisture content is determined by heating a sample in an air oven and then comparing the weight of the sample before and after the heating process. The amount of weight lost is the moisture content, which is typically expressed as a percentage.
The protein content of wheat flour can be important to flour users, as it can contribute to water absorption and gluten strength. Protein content can also affect finished product texture and appearance. Different levels of protein are needed for different types of products. Protein content is determined by burning a sample in a nitrogen combustion unit, and then the use of a formula to convert the results to protein percentage in the sample.
Ash content is an indicator of mineral content in flour. Ash is mainly concentrated in the bran coat of wheat kernels. Ash content is determined by incinerating a sample in a small furnace, and then comparing the starting weight with the weight of the residue remaining, and is expressed as a percentage. Ash content can affect finished product color. Products in need of a very white flour require a lower ash content. Whole wheat graham flour has a high ash content.
The falling number of a flour sample is a measure of the enzyme activity in the flour. A higher falling number indicates lower enzyme activity, and vice versa. Different products require different levels of enzyme activity. Falling number is a measure of viscosity, and is measured by mixing a sample of flour and distilled water to form a slurry, then heated and stirred in a water bath, and then measuring the time it takes the stirrer to drop.
The water absorption of a flour is an indicator of the amount of water needed to make a dough. Absorption can be measured using a farinograph, which can also provide information about mixing tolerance and requirements.
