Optimization of protein extraction from flaxseed cake using deep eutectic solvent and its effect on structural and functional properties

El Mehdi Raoui; Milad Hadidi; Xuanhui Wang; Jose L. Toca-Herrera; Alexander Einschütz Lopez; Christian Leopold Lengauer; Sarah Schlosser; Karin Hummel; Fawzan Sigma Aurum; Ebrahim Razzazi-Fazeli; Marc Pignitter

doi:10.1016/j.foodchem.2026.149989

Optimization of protein extraction from flaxseed cake using deep eutectic solvent and its effect on structural and functional properties

El Mehdi Raoui
, Milad Hadidi (Corresponding author)
, Xuanhui Wang
, Jose L. Toca-Herrera
, Alexander Einschütz Lopez
, Christian Leopold Lengauer
, Sarah Schlosser
, Karin Hummel
, Fawzan Sigma Aurum
, Ebrahim Razzazi-Fazeli
, Marc Pignitter (Corresponding author)

Publications: Contribution to journal › Article › Peer Reviewed

Abstract

Ultrasound-assisted deep eutectic solvent (UDES) extraction was explored as a sustainable strategy to recover proteins from flaxseed cake, a by-product of oil production. Optimised extraction conditions (30,1 liquid-to-solid ratio, 75 °C, 60 min) resulted in a protein content of 57.78%, in comparison to conventional alkaline extraction with 43.54%. Proteomic and amino acid analyses revealed a balanced composition rich in 2S albumin (conlinins), known for their nutritional quality and potential to form bioactive peptides. UDES-modified proteins showed improved thermal stability and distinctive smooth, low-porosity morphology compared to alkaline-derived isolates. Whilst all samples exhibited similar protein bio-accessibility (approximately 60%) under simulated digestion, the proteins obtained by UDES displayed reduced emulsifying and water/oil binding capacities, suggesting limited functional potential. Thus, UDES extraction offers an environmentally friendly route for converting flaxseed cake into high-value protein ingredients, though further optimization is needed to tailor functionality for specific food applications.

Original language	English
Article number	149989
Journal	Food Chemistry
Volume	522
DOIs	https://doi.org/10.1016/j.foodchem.2026.149989
Publication status	Published - 1 Sept 2026

Funding

This research was funded in whole or in part by the Austrian Science Fund (FWF) [10.55776/P34512]. The authors acknowledge Yuuki Takatsuna, Dr. Federica Cappa and Salvatore Caterino for their technical assistance during the TGA and FTIR analysis. For open access purposes, the author has applied a CC BY public copyright license to any author accepted manuscript version arising from this submission.

Funders	Funder number
Fonds zur Förderung der wissenschaftlichen Forschung (FWF)	10.55776/P34512

Austrian Fields of Science 2012

104009 Food chemistry
104002 Analytical chemistry

Keywords

By-product valorisation
Emulsifying capacity
In vitro bioaccessibility
Proteomic analysis
Ultrasound cavitation

Access to Document

10.1016/j.foodchem.2026.149989

Cite this

Raoui, E. M., Hadidi, M., Wang, X., Toca-Herrera, J. L., Lopez, A. E., Lengauer, C. L., Schlosser, S., Hummel, K., Aurum, F. S., Razzazi-Fazeli, E., & Pignitter, M. (2026). Optimization of protein extraction from flaxseed cake using deep eutectic solvent and its effect on structural and functional properties. Food Chemistry, 522, Article 149989. https://doi.org/10.1016/j.foodchem.2026.149989

@article{6d44ee474fe446239ad940b051d85d49,

title = "Optimization of protein extraction from flaxseed cake using deep eutectic solvent and its effect on structural and functional properties",

abstract = "Ultrasound-assisted deep eutectic solvent (UDES) extraction was explored as a sustainable strategy to recover proteins from flaxseed cake, a by-product of oil production. Optimised extraction conditions (30,1 liquid-to-solid ratio, 75 °C, 60 min) resulted in a protein content of 57.78\%, in comparison to conventional alkaline extraction with 43.54\%. Proteomic and amino acid analyses revealed a balanced composition rich in 2S albumin (conlinins), known for their nutritional quality and potential to form bioactive peptides. UDES-modified proteins showed improved thermal stability and distinctive smooth, low-porosity morphology compared to alkaline-derived isolates. Whilst all samples exhibited similar protein bio-accessibility (approximately 60\%) under simulated digestion, the proteins obtained by UDES displayed reduced emulsifying and water/oil binding capacities, suggesting limited functional potential. Thus, UDES extraction offers an environmentally friendly route for converting flaxseed cake into high-value protein ingredients, though further optimization is needed to tailor functionality for specific food applications.",

keywords = "By-product valorisation, Emulsifying capacity, In vitro bioaccessibility, Proteomic analysis, Ultrasound cavitation",

author = "Raoui, \{El Mehdi\} and Milad Hadidi and Xuanhui Wang and Toca-Herrera, \{Jose L.\} and Lopez, \{Alexander Einsch{\"u}tz\} and Lengauer, \{Christian Leopold\} and Sarah Schlosser and Karin Hummel and Aurum, \{Fawzan Sigma\} and Ebrahim Razzazi-Fazeli and Marc Pignitter",

note = "Publisher Copyright: {\textcopyright} 2026 The Authors. Accession Number WOS:001800304400001 PubMed ID 42296654 ",

year = "2026",

month = sep,

day = "1",

doi = "10.1016/j.foodchem.2026.149989",

language = "English",

volume = "522",

journal = "Food Chemistry",

issn = "0308-8146",

publisher = "ELSEVIER SCI LTD",

}

TY - JOUR

T1 - Optimization of protein extraction from flaxseed cake using deep eutectic solvent and its effect on structural and functional properties

AU - Raoui, El Mehdi

AU - Hadidi, Milad

AU - Wang, Xuanhui

AU - Toca-Herrera, Jose L.

AU - Lopez, Alexander Einschütz

AU - Lengauer, Christian Leopold

AU - Schlosser, Sarah

AU - Hummel, Karin

AU - Aurum, Fawzan Sigma

AU - Razzazi-Fazeli, Ebrahim

AU - Pignitter, Marc

PY - 2026/9/1

Y1 - 2026/9/1

N2 - Ultrasound-assisted deep eutectic solvent (UDES) extraction was explored as a sustainable strategy to recover proteins from flaxseed cake, a by-product of oil production. Optimised extraction conditions (30,1 liquid-to-solid ratio, 75 °C, 60 min) resulted in a protein content of 57.78%, in comparison to conventional alkaline extraction with 43.54%. Proteomic and amino acid analyses revealed a balanced composition rich in 2S albumin (conlinins), known for their nutritional quality and potential to form bioactive peptides. UDES-modified proteins showed improved thermal stability and distinctive smooth, low-porosity morphology compared to alkaline-derived isolates. Whilst all samples exhibited similar protein bio-accessibility (approximately 60%) under simulated digestion, the proteins obtained by UDES displayed reduced emulsifying and water/oil binding capacities, suggesting limited functional potential. Thus, UDES extraction offers an environmentally friendly route for converting flaxseed cake into high-value protein ingredients, though further optimization is needed to tailor functionality for specific food applications.

AB - Ultrasound-assisted deep eutectic solvent (UDES) extraction was explored as a sustainable strategy to recover proteins from flaxseed cake, a by-product of oil production. Optimised extraction conditions (30,1 liquid-to-solid ratio, 75 °C, 60 min) resulted in a protein content of 57.78%, in comparison to conventional alkaline extraction with 43.54%. Proteomic and amino acid analyses revealed a balanced composition rich in 2S albumin (conlinins), known for their nutritional quality and potential to form bioactive peptides. UDES-modified proteins showed improved thermal stability and distinctive smooth, low-porosity morphology compared to alkaline-derived isolates. Whilst all samples exhibited similar protein bio-accessibility (approximately 60%) under simulated digestion, the proteins obtained by UDES displayed reduced emulsifying and water/oil binding capacities, suggesting limited functional potential. Thus, UDES extraction offers an environmentally friendly route for converting flaxseed cake into high-value protein ingredients, though further optimization is needed to tailor functionality for specific food applications.

KW - By-product valorisation

KW - Emulsifying capacity

KW - In vitro bioaccessibility

KW - Proteomic analysis

KW - Ultrasound cavitation

UR - https://www.scopus.com/pages/publications/105041642854

U2 - 10.1016/j.foodchem.2026.149989

DO - 10.1016/j.foodchem.2026.149989

M3 - Article

AN - SCOPUS:105041642854

SN - 0308-8146

VL - 522

JO - Food Chemistry

JF - Food Chemistry

M1 - 149989

ER -

Optimization of protein extraction from flaxseed cake using deep eutectic solvent and its effect on structural and functional properties

Abstract

Funding

Austrian Fields of Science 2012

Keywords

Access to Document

Other files and links

Cite this