Reverse micelles extraction of hemp protein isolate: Impact of defatting process on protein structure, functionality, and aromatic profile

Hempseed is becoming an emerging crop because of the potential utilization of its multifunctional constituents particularly hemp proteins in commercial products. Recently, reverse micelles (RMs) extraction technology has been introduced into protein extraction because of its convenience and low-cost nature. The current study aims to investigate the influence of the defatting process on the extraction performance, chemical compositions, physicochemical properties, and aromatic profile of hemp protein isolate (HPI) extracted via RMs extraction. Our results suggest that defatting is not a necessary step for RMs to extract protein from hemp flours in terms of extraction performance. HPIs obtained from non-defatted hemp flour (ND-HF) and defatted hemp flour (D-HF) exhibited great similarities in proximate composition and protein subunits, and functional properties (isoelectric point, solubility, emulsifying, foaming, and thermal stability). Meanwhile, a higher percentage of β-sheet and a greater surface hydrophobicity were observed in HPI obtained from ND-HF. In addition, the gel formed by HPI from ND-HF displayed a higher least gelling concentration (4% w/v) with yellowish color and stronger gel strength as compared to D-HF HPI. Concerning aroma profile, HPI from ND-HF yielded a higher number and content of aromatic compounds than the counterpart. The current research implies that RMs could be applied to directly extract HPI from non-defatted hemp flours without largely impacting the functionality of the protein, thus giving a great potential of the eco-friendly way for protein extraction.