What is the milling loss and refraction percentage in wheat flour industry?

In wheat milling industry, milling losses and refraction are important factors that can affect the yield of flour and its overall quality.

Milling loss:

Milling loss refers to the portion of the wheat grain that is lost during the milling process. It includes various streams such as bran, shorts, screenings, and dust. These components are separated from the endosperm, which is the primary part of the wheat grain used to produce flour.

The percentage of milling loss can vary depending on several factors, including the wheat variety, milling equipment used, and the desired flour extraction rate. Generally, milling loss can range between 10% to 18% of the total wheat grain weight.

Refraction percentage:

Refraction refers to the separation of endosperm fragments of different sizes and densities during the milling process. This separation is based on the principle that larger and heavier endosperm particles tend to settle lower in the flour stream, while smaller and lighter fragments are suspended higher.

The refraction percentage represents the proportion of endosperm fragments that are classified as "refraction" during milling. These fragments are removed from the flour stream to produce higher quality and uniform flour.

The refraction percentage can vary depending on factors such as the wheat variety, milling equipment, and the desired flour specifications. Typically, the refraction percentage ranges between 3% to 5% of the total wheat grain weight.

By controlling and optimizing the milling process, flour millers can minimize milling losses and achieve efficient utilization of the wheat grain, while also ensuring the desired flour quality and extraction rate.