Heliaflor® Cereal Pur Small

Protein concentrates are produced by removing non-protein components, which increases the relative protein content. For pulses, dry fractionation by air classification is usually the main method; for oilseeds, de-oiling the raw material is the decisive process step.

Oilseeds: de-oiling as the central step

Sunflower kernels (Heliaflor®) and soya contain a high proportion of oil in addition to protein. To produce a protein concentrate, the oil is therefore first removed by mechanical pressing, by extraction (e.g. with CO₂ or ethanol) or by a combination of both methods. This yields press cakes or de-oiled flours in which the protein is relatively enriched.

The protein content and quality of the concentrate depend, among other things, on how completely the oil is removed, how much hull material remains in the product and the heat and other process conditions to which the material is exposed.

Pulses: fractionation by air classification

Peas and faba beans are cleaned and milled into flour. This flour is then usually separated by particle size and density using air classification. The finer particles are typically richer in protein and are separated off as the protein fraction, while the coarser particles contain mainly starch.

Dry fractionation requires little water and largely preserves the properties of the proteins. However, the achievable protein content is limited and depends on factors such as the composition of the raw material, the degree of milling and the process conditions.

Quality characteristics

Protein content alone does not fully describe the quality of a concentrate. Amino acid composition, digestibility, solubility and functional properties are equally important. In the dry fractionation of pulses, the proteins often remain comparatively unchanged; in oilseeds, de-oiling and further processing can influence the functional properties.