Crude Fibre Analysis

Crude fibre analysis is one of the oldest methods used to estimate the indigestible portion of plant materials in food and feed.
Crude fibre mainly represents cellulose and lignin, with small amounts of hemicellulose remaining after chemical treatment. It is used as a general indicator of structural fibre content.

In laboratory analysis, the sample is treated with dilute acid followed by dilute alkali. This process removes most digestible components such as sugars, starch, proteins, and fats.
The remaining residue is dried, weighed, and then incinerated to remove mineral content. The loss in weight after ashing is used to calculate crude fibre.

Crude fibre does not measure all fibre components. Some structural carbohydrates are lost during analysis, which leads to an underestimation of total fibre content.
Because of this limitation, crude fibre is often used alongside other fibre fractions such as NDF and ADF.

Crude fibre testing is commonly used in:
‣ Animal feed quality control
‣ Raw material screening
‣ Routine nutritional analysis