Physicochemical, Structural, and Functional Properties of Hemp Protein vs Several Commercially Available Plant and Animal Proteins: A Comparative Study
Yixiang Xu, Edward Sismour, Julia Wilkins Britland, Anisa Sellers, Zaid Abraha-Eyob, Adnan B. Yousuf, Qinchun Rao, Ji-Min Kim, Wei Zhao
Abstract
The physicochemical, structural, and functional properties of hemp seed protein were investigated and compared with soy, pea, whey, and egg proteins. Hemp protein exhibited the lowest total (67.1 g/100 g) and essential amino acid contents (23.1 g/100 g) but the highest arginine level (9.17 g/100 g). Hemp protein had a β-sheet conformation as the predominant secondary structure and demonstrated four major bands located at ∼18, ∼20, and ∼34–36 kDa in an SDS-PAGE profile, corresponding to the basic and acidic subunits of edestin, respectively. The highly compact structure of hemp protein along with a higher surface hydrophobicity (H0) of 750 × 104 au and −SH content of 34.85 μmol/g may explain the low water absorption capacity (372.41 g/100 g) and protein solubility, but a high oil absorption capacity (135.48 g/100 g) and emulsification activity index of 48.40 m2/g are found. Our results support the potential use of hemp protein in various protein-rich food products. However, appropriate processing technologies are needed to modify its structure and functionality.