Proteins are vital and therefore an indispensable part of the human diet. Due to the worldwide population growth, the demand for protein is increasing enormously. This demand can no longer be met by animal proteins alone. Vegetable protein, on the other hand, is versatile and consistent with a vegetarian or vegan lifestyle. Thus, alternative sources of protein will become increasingly important to meet the protein needs of the population. One such alternative source of protein is plant-based proteins, which are mainly obtained from wheat, soy, peas, lentils or other pulses. In order to make optimal use of their protein content, the process of protein shifting (or dry fractionation) was developed. Ultra-fine grinding and subsequent classifying produces fractions whose protein content is considerably higher than in the starting material. These protein- and starch-rich special flours are then used as the basis for vegan burger patties, lupine cutlets and many other plant-based foods.



Perfectly harmonised machines

Hosokawa Alpine has developed various processes for dry fractionation. Our experts have been working on this topic since the 1970s. These many years of experience bring our customers several decisive advantages: The project time is shortened, and customers also receive a high degree of planning security. If their requirements change, we have the necessary flexibility to respond to the new situation.

But how does protein shifting work? The enrichment of protein in a dry process by means of grinding and classifying is an environment-friendly and cost-efficient method. By means of perfectly coordinated machines, the proteins in wheat and pulses such as peas, broad beans, lupins, lentils and chick peas are enriched, and the proteins are separated from other components.


With our partners we can cover the complete process

The production of protein concentrates – for example with peas – is a high-tech process that involves various steps for which high performance machines and systems are required. Hosokawa Alpine’s competences lie in the dry fractionation process. Hosokawa Micron BV offers machines and systems for mixing, agglomeration and sterilization, that are needed in the downstream processes for the final applications. Hosokawa Solids supports customers throughout the process with solutions for storage, conveying, weighing and dosing. If you are interested in a complete dry fractionation process, we can offer this together with our partner Bühler. In the picture below you can find the pulse processing value chain for dry and wet fractionation as well as the final applications of the products.


with ZPS air classifier mill and ATP air classifier (precision process)


Hosokawa Alpine’s special know-how is to grind in the “right” way to deagglomerate the smaller protein (~3μm) and the larger starch particles (15 – 40 μm) and then to fractionate the fine fraction (mainly the protein particles) and the coarse fraction (mainly the starch particles). Hosokawa Alpine’s dry fractionation of proteins (precision process) consists of an efficient fine grinding with the Zirkoplex ZPS classifier mill and a high-performance classification of this finely ground product with the Turboplex ATP classifier. As a result, there are two products: a fine product (protein concentrate) and a coarse product (starch concentrate).

Advantages of dry fractionation

  • Efficient separation of protein and starch
  • Energy efficient operation
  • No water consumption
  • Economical by-products
  • No e-numbers required
  • Chemical-free processing

Example of a typical system for dry fractionation with ZPS and ATP

  1. Feeding bin
  2. Feeding screw
  3. Metal separator
  4. ZPS classifier mill
  5. ZPS automatic filter
  6. ZPS blower
  7. ATP air classifier
  8. ATP automatic filter
  9. ATP blower
  10. Control cabinet

(a) Feeding product
(b) Low-protein fraction
(c) High-protein fraction


with CW II pin mill and ATP air classifier (standard process)

Hosokawa Alpine’s standard process for the dry fractionation of proteins consists of efficient fine grinding with the Contraplex CW II pin mill and high-performance classification of this finely ground product with the Turboplex ATP classifier. For some products with a high fibre and/or oil content, the Contraplex CW II is the mill of choice for efficient deagglomeration. For pulses, the standard process with the Contraplex CW II pin mill impresses with its compact installation (compared to the precision process with the ZPS classifier mill) as well as low energy consumption and low investment costs. On the other hand, there are limits: The fineness and protein values are in the medium range, the product temperature is higher and pin mills are more susceptible to wear than classifier mills.

Standard process with CW II pin mill Precision process with ZPS classifier mill
Compact installation Flexible installation, but needs more space
Low investment Bigger investment
Medium fineness and protein values High fineness and protein values
Higher product temperatures Cooling for temperature-sensitive products
Sensitive to wear Wear protection possible

Example of a typical system for protein shifting with CW II and ATP

  1. Feeding bin
  2. Feeding screw
  3. Metal separator
  4. CW II pin mill
  5. ATP air classifier
  6. Automatic filter
  7. Blower
  8. Control cabiner

(a) Feeding product
(b) Low-protein fraction
(c) High-protein fraction


Customised processes for dry fractionation

There are several other sources of protein that were previously only used for the feed industry. The challenge of today is to bring this valuable protein back for human consumption. Especially under the aspect of sustainability, upcycling of food side streams is desirable.

Examples are


    • Sunflower meal
    • Pseudo cereals (e. g. Quinoa)
    • Guar split
    • Locust bean gum split
    • Food side streams from brewery processes
    • Food side streams from oil extraction processes

But not only protein is interesting for dry fractionation. Some other valuable ingredients can also be fractionated (e. g. fiber fractions). Moreover, the (fibrous) hulls of pulses can be finely ground with the ZPS classifier mill for their final application (e.g. pet food, cookies and brownies). Future projects may revolve around the field of wet/dry fractionation.


Customised processes for protein dry fractionation

Customised processes are required for the dry fractionation of products from cereals and grains. Contact us to find the best possible solution for your product!

Wheat and rye: For wheat and rye you can choose the standard process with the Contraplex CW II pin mill and the Turboplex ATP classifier or, if you are aiming for higher protein contents, the precision process. Depending on the amount of protein before processing, different amounts / yield of protein are obtained.

Oats and barley: Oats and barley contain beta-glucan as a valuable ingredient. Due to the high fat content of oats, it is mandatory to use the Contraplex CW II pin mill for fine grinding (standard process with CW II and ATP). A further de-fatting step of oats can additionally improve the process properties for an efficient fractionation. As opposed to the protein dry fractionation the beta-glucan is here collected in the coarse fraction. To obtain higher beta-glucan values, the grinding-classification process can be repeated several times.

Soy: Hosokawa Alpine can offer various solutions for soy processing:

    • Pre-treatment: Pre-Crushing of the soy beans and dehulling of soy beans
    • Fine grinding of: full-fat soya beans, roasted soy beans, extracted soya flakes, extruded soya flakes (Wenger Process) and soy protein concentrates (SPC)

Rice: Process technology for tomorrow includes fine grinding of rice in its various forms: may it be rice hulls, rice flakes, rice protein or rice starch.