Water-Only Fractionation of Hempseed: Effect of Phytate on Ingredients Properties and Separation

The increasing demand for alternative plant-based ingredients for foods drives the need for sustainable processing methods. In this study, hempseeds were fractionated using a water-only process, involving soaking, blending, filtering, and centrifuging to produce hempseed meal, cream, serum, and pellet fractions. Composition analysis was performed on each fraction, and the cream and pellet fractions were thoroughly characterized. The results indicated that the cream fraction, mainly composed of oil bodies (OBs), was high in oil (98.6±1.5% d.b.) and low in proteins (2.4±0.8% d.b.). ζ-potential and particle size experiments suggested that a relatively purified OBs cream can be obtained through a fractionation process where only water is needed, and that relatively large OBs were observed across the pH range studied. On the other hand, the pellet can be considered a hempseed protein concentrate (73.8±1.9% d.b. of proteins), which was also relatively high in phytate (12.6±0.8% d.b.). It is suggested that the proteins precipitated following a different mechanism than conventional isoelectric precipitation: in the water-only fractionation of hempseed, phytate formed insoluble ternary complexes with proteins and cations, such as magnesium or calcium, favoring the separation between ingredients, which is confirmed after phytase and phytate treatments. Moreover, Coherent anti-Stokes Raman scattering microscopy images showed that phytate interacted with OBs when added to the cream fraction, reducing particle size, increasing packing of OBs, and extending storage time, interactions that were further evidenced through ζ-potential and creaming stability analysis at different pH values. This study highlights the potential of mild processing for hempseed and demonstrates the role of phytate in enhancing the stability and functionality of plant-based food ingredients and contributing to sustainable food processing methods.