The impact of hempseed dehulling on chemical composition, structure properties and aromatic profile of hemp protein isolate

Hempseed protein has attracted increasing attention in both scientific and industrial field because of its high nutritional value. In the current study, the influence of dehulling process on the chemical composition, structure and functional properties of hempseed protein isolate (HPI) was determined by using SDS-PAGE, SEC-HPLC-UV/RI/MALS, CD spectroscopy and DSC. The result demonstrated that dehulling process significantly increased the extraction and protein recovery yields of HPI. Meanwhile, dehulled HPI also exhibited a higher protein purity and Arg/Lys ratio with improved color. No significant impact on protein composition and structure was observed upon seed dehulling, but HPI extracted from the dehulled seeds showed a reduced thermal stability as compared to non-dehulled HPI. The aromatic profile of HPI was determined by HS-SPME-GC-MS, and the data suggested that dehulled HPI accumulated more terpenes and less lipid oxidation volatiles than non-dehulled HPI. These findings indicated that dehulling process greatly enhances the extraction yield with higher protein content and more characteristic aroma of HPI. The current study for the first time provides valuable information about the influence of dehulling processing on the properties of HPI, which will facilitate further research and application of hempseed and its valued added ingredients in both academic and industry field.