The importance of dehulling

Dehulling is a crucial stage in the processing of agricultural or agri-food biomass, as it releases the essential components of these raw materials. This stage is extremely important for a number of reasons.

Separation of non-food parts

In many agricultural crops, a large part of the biomass is not directly edible, such as husks, shells, stems, etc. Dehulling separates these undesirable parts from the edible part, making the raw materials more suitable for human consumption or industrial processing.

Access to the nutrient

Dehulling can provide easier access to the nutrients present in the biomass. In the case of cereals, for example, the grains are surrounded by a husk (the bran) that contains fibre and other nutrients. Hulling removes this husk to access the grain itself, which is rich in starch and protein.

Extraction of oils and fats

In the food industry, hulling is essential for extracting the oils and fats present in certain raw materials, such as oilseeds (e.g. sunflower seeds, soya beans, rapeseed). Dehulling releases these oils, which are then used in the production of edible oils, margarine, etc.

Improving digestibility

Dehulling can also improve the digestibility of food. By removing indigestible or difficult-to-digest parts, food is made easier for the body to assimilate.

Reducing waste

By removing the inedible parts of the biomass, hulling helps to reduce agricultural waste, which in turn benefits the environment by reducing waste and optimising the use of resources.

Preparation for industrial processing

In the agri-food industry, hulling is often the first stage in the production chain, as it prepares the raw material for the subsequent stages of processing, such as milling, cooking, fermentation and so on.

In short, dehulling is an essential stage in the processing of agricultural and agri-food raw materials, as it releases essential components while eliminating undesirable parts. This improves the quality of finished products, reduces waste and boosts the efficiency of food production.


Raw material preparation


Grains or oilseeds, such as rice, wheat, barley, or sunflower, are prepared for the process by removing impurities, debris, and any foreign matter.

Initial grinding


The raw materials undergo an initial grinding stage. This can be done using specific grinders that break the outer husks without necessarily removing them completely. This preliminary step aims to weaken the husks, facilitating the subsequent hulling process.

Sorting and classification


After the initial grinding, the materials are directed to sorting and classification equipment. These devices can be sieves, sifters, or separators that separate particles based on their size. This helps to separate the outer parts of the grains from the internal parts.

Fine grinding


The resulting fractions are then subjected to finer grinding. This process aims to further refine the separation between husks and the internal parts of the grains. The grinders used can be adjusted to control particle size.

Fraction separation


After fine grinding, the obtained fractions are directed to more precise separation devices. These devices may use mechanical forces, air currents, or other methods to separate husks from the internal parts. The lighter husks can be blown or suctioned away, while the heavier internal parts are recovered.

Quality control


Tout au long du processus, des systèmes de contrôle de la qualité peuvent être mis en place pour s’assurer que la séparation des fractions est efficace et que le produit final répond aux normes requises.

Storage of further processing


The obtained fractions, often consisting of the internal parts of the grains without their husks, can be stored or directed to other processing processes as needed. These fractions can be used in food production, the biofuel industry, or other applications.

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