Simultaneous extraction of hempseed oil bodies and protein concentrate through mild phytate-driven water-only fractionation

• Water-only fractionation yields a cream of pure oil bodies and a protein fraction. • Endogenous phytate plays an active role in the separation process. • Phytate stabilizes oil bodies, reducing particle size and extending shelf life. • Ternary protein–cation–phytate complexes precipitate during the water-only process. • Water-only processing prevents the protein aggregation seen in alkaline procedures. The increasing demand for plant-based ingredients motivates the need for sustainable processing of oil-rich seeds, simultaneously obtaining oil bodies (OBs) and protein fractions. In this study, hempseeds were fractionated using a water-only process to produce hempseed meal, cream (rich in OBs), serum, and a protein-rich pellet. The cream fraction was high in oil (98.6 ± 1.5 % dry basis, d.b.) and low in proteins (2.4 ± 0.8 % d.b.), predominantly OBs surface proteins. ζ-potential and particle size experiments suggested that a purified OBs cream was obtained, with large OBs observed across the pH range. The pellet, considered a hempseed protein concentrate (HPC), contained 73.8 ± 1.9 % d.b. of proteins. It was mainly composed of the storage protein edestin and was high in phytate. HPC likely precipitated through a mechanism different from conventional isoelectric precipitation of proteins, forming insoluble protein-cation-phytate complexes that facilitated their separation from OBs, as confirmed by phytase and phytate treatments. Moreover, coherent anti-Stokes Raman scattering microscopy images showed that phytate interacted with OBs when added to the cream fraction, seemingly having a reduced particle size, increasing OBs packing and extending storage time. This study highlights the potential of mild hempseed processing and the role of phytate in fractionating and enhancing the stability of food ingredients.