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Heat induced structural transitions of PA1 and PA2 albumins from pea

Li, Ruifen ; Atıl, Gökhan Uğur ; Pal, Antara ; Jones, Nykola C. ; Sørensen, Henrik Vinther LU ; Hoffmann, Søren Vrønning ; Pedersen, Jan Skov and Corredig, Milena LU (2026) In Food Hydrocolloids 175.
Abstract

Pea albumins are the soluble fraction of pea proteins, recovered as a side stream of the isoelectric precipitation. The time-resolved heat-induced structural transitions of the whole fraction of pea albumin (PA) were studied by evaluating the structure of the two main fractions, PA1 and PA2. Synchrotron radiation circular dichroism (SR-CD) spectroscopy showed that the secondary structure signature for PA1 remained unchanged at temperatures up to 85 °C. In contrast, PA2 underwent a change in secondary structure between 45 and 70 °C. These thermal transitions were also confirmed by Nano Differential Scanning Calorimetry (Nano-DSC). Small-angle X-ray scattering (SAXS) in situ experiments were also carried out, and high-resolution... (More)

Pea albumins are the soluble fraction of pea proteins, recovered as a side stream of the isoelectric precipitation. The time-resolved heat-induced structural transitions of the whole fraction of pea albumin (PA) were studied by evaluating the structure of the two main fractions, PA1 and PA2. Synchrotron radiation circular dichroism (SR-CD) spectroscopy showed that the secondary structure signature for PA1 remained unchanged at temperatures up to 85 °C. In contrast, PA2 underwent a change in secondary structure between 45 and 70 °C. These thermal transitions were also confirmed by Nano Differential Scanning Calorimetry (Nano-DSC). Small-angle X-ray scattering (SAXS) in situ experiments were also carried out, and high-resolution structural models of PA1 and PA2, derived from the AlphaFold Protein Structure Database, were used for data analysis. PA1 maintained a consistent local structure with a radius of gyration ∼17 Å across all temperatures, but formed small soluble aggregates above 60 °C, as evidenced by an upturn at low q. PA2 scattering resulted from its dimeric structures and transitioned to unfolded structures after 60 °C. The unfractionated PA scattering showed good agreement with a linear combination of PA1 and PA2 scattering. This was also confirmed by the structural behavior of the purified PA1+PA2 mixture, which closely resembled that of PA2, though the PA2 component remained partially folded even after heating above 70 °C. This study brings new knowledge on the contribution of the two main components of pea albumins in the thermal behavior of this novel extract, with great potential to be used as a functional food ingredient.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
PA1, PA2, Pea albumins, SAXS, Secondary structure, Structure, Thermal behaviors
in
Food Hydrocolloids
volume
175
article number
112498
publisher
Elsevier
external identifiers
  • scopus:105028654890
ISSN
0268-005X
DOI
10.1016/j.foodhyd.2026.112498
language
English
LU publication?
yes
id
ad08843b-d884-4114-961f-11d46a47cd7d
date added to LUP
2026-02-18 09:03:31
date last changed
2026-02-18 09:04:28
@article{ad08843b-d884-4114-961f-11d46a47cd7d,
  abstract     = {{<p>Pea albumins are the soluble fraction of pea proteins, recovered as a side stream of the isoelectric precipitation. The time-resolved heat-induced structural transitions of the whole fraction of pea albumin (PA) were studied by evaluating the structure of the two main fractions, PA1 and PA2. Synchrotron radiation circular dichroism (SR-CD) spectroscopy showed that the secondary structure signature for PA1 remained unchanged at temperatures up to 85 °C. In contrast, PA2 underwent a change in secondary structure between 45 and 70 °C. These thermal transitions were also confirmed by Nano Differential Scanning Calorimetry (Nano-DSC). Small-angle X-ray scattering (SAXS) in situ experiments were also carried out, and high-resolution structural models of PA1 and PA2, derived from the AlphaFold Protein Structure Database, were used for data analysis. PA1 maintained a consistent local structure with a radius of gyration ∼17 Å across all temperatures, but formed small soluble aggregates above 60 °C, as evidenced by an upturn at low q. PA2 scattering resulted from its dimeric structures and transitioned to unfolded structures after 60 °C. The unfractionated PA scattering showed good agreement with a linear combination of PA1 and PA2 scattering. This was also confirmed by the structural behavior of the purified PA1+PA2 mixture, which closely resembled that of PA2, though the PA2 component remained partially folded even after heating above 70 °C. This study brings new knowledge on the contribution of the two main components of pea albumins in the thermal behavior of this novel extract, with great potential to be used as a functional food ingredient.</p>}},
  author       = {{Li, Ruifen and Atıl, Gökhan Uğur and Pal, Antara and Jones, Nykola C. and Sørensen, Henrik Vinther and Hoffmann, Søren Vrønning and Pedersen, Jan Skov and Corredig, Milena}},
  issn         = {{0268-005X}},
  keywords     = {{PA1; PA2; Pea albumins; SAXS; Secondary structure; Structure; Thermal behaviors}},
  language     = {{eng}},
  publisher    = {{Elsevier}},
  series       = {{Food Hydrocolloids}},
  title        = {{Heat induced structural transitions of PA1 and PA2 albumins from pea}},
  url          = {{http://dx.doi.org/10.1016/j.foodhyd.2026.112498}},
  doi          = {{10.1016/j.foodhyd.2026.112498}},
  volume       = {{175}},
  year         = {{2026}},
}