Dry fractionation retains native protein functionality primarily because it eliminates the harsh conditions used in conventional wet protein extraction, keeping protein bodies and protein tertiary/quaternary structures intact.
No aqueous alkaline/acidic extraction or solvent use
Wet processes use water, pH adjustment, salts or chemical additives to solubilise and precipitate proteins. Extreme pH disrupts hydrogen bonds and hydrophobic interactions, causing partial unfolding and denaturation. Dry fractionation only uses mechanical milling and air classification, without dissolving the protein matrix, so protein molecules remain in their native state.
Minimal thermal exposure
Dry fractionation operates at near-ambient temperature. While ultra-fine grinding generates minor frictional heat, well-controlled process parameters limit temperature rise and avoid thermal denaturation. In contrast, wet processing often includes heating, pasteurisation or spray drying steps that degrade protein functionality.
Protein bodies stay structurally intact
Legume proteins naturally exist inside membrane-bound protein bodies. Selective milling liberates these protein bodies from starch granules and cell wall fibre, rather than breaking down individual protein molecules. The native packed structure inside protein bodies is maintained, preserving solubility, emulsifying capacity, foaming properties and water-binding behaviour.
No precipitation and re-aggregation steps
Wet isolation requires protein precipitation followed by drying, which frequently triggers irreversible protein aggregation and loss of native functional attributes. Dry fractionation directly separates particulate protein bodies as a solid powder; there is no solubilisation-precipitation cycle that damages protein conformation.
Anti-nutrient profile remains unmodified (no washing-induced structural shift)
Though dry fractionation cannot remove soluble anti-nutrients, it does not introduce structural changes to protein molecules from washing, ion exchange or pH shifts. Protein surface hydrophobicity and charge distribution stay close to the native seed state.
Excessive ultrafine grinding can mechanically damage protein bodies and impair functionality. Process parameters must be carefully controlled to avoid mechanical denaturation.
