Structural, physicochemical and functional properties of quinoa, buckwheat and amaranth protein isolates: A comparative study

Xinyi Yan; Fan Zhu

doi:10.1016/j.foodchem.2025.145301

Structural, physicochemical and functional properties of quinoa, buckwheat and amaranth protein isolates: A comparative study

Food Chem. 2025 Jun 23:491:145301. doi: 10.1016/j.foodchem.2025.145301. Online ahead of print.

Authors

Xinyi Yan¹, Fan Zhu²

Affiliations

¹ School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
² School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand. Electronic address: fzhu5@yahoo.com.

PMID: 40577920
DOI: 10.1016/j.foodchem.2025.145301

Abstract

This study investigated the structural and physicochemical properties of protein isolates of white quinoa (WQPI), red quinoa (RQPI), common buckwheat (CBPI), Tartary buckwheat (TBPI), and amaranth of A. hypochondriacus (AhPI) and A. caudatus (AcPI). WQPI showed superior water (179 %) and oil (185 %) binding capacities, while amaranth proteins exhibited higher solubility and foaming capacities. CBPI displayed the lowest solubility, and capacity and stability of both emulsifying and foaming, likely due to its largest particle size (66.1 μm), but formed the most robust gel network. In contrast, TBPI had the smallest particle size (15.7 μm), but its high phenolic content interfered with surface activity resulting in low foaming and emulsifying stability (40.7 %). Principal component analysis confirmed strong correlations between structural and functional traits. These findings emphasize the critical roles of particle size, surface hydrophobicity, and structural interactions in determining protein functionalities, offering valuable insights for the application of pseudocereal proteins in food formulations.

Keywords: Amaranthus hypochondriacus; Chenopodium quinoa; Fagopyrum esculentum; Physicochemical property; Plant protein; Principal component analysis; Pseudocereal protein; Tartary buckwheat.