Micronization-assisted pulsed electric field treatment on functional and structural modification of red pepper seed protein isolates
- 1Guangdong Provincial Key Laboratory of Intelligent Food Manufacturing, School of Food Science and Engineering, Foshan University, Foshan, China
- 2School of Food Science and Engineering, South China University of Technology, Guangzhou, China
- 3Department of Food Science & Nutrition, College of Food and Agricultural Sciences, King Saud University, Riyadh, Saudi Arabia
Abstract
Background: Red pepper seeds are an underutilized source of plant proteins with functional potential, but their poor solubility and limited functionality restrict food applications. This study investigated the effects of micronization-assisted pulsed electric field (PEF) treatment on the structural, physicochemical, and functional properties of red pepper seed protein isolates (RPSPIs).
Methods: RPSPIs were subjected to micronization pretreatment followed by PEF treatment under different electric field strengths and processing conditions. The effects of combined treatment on surface hydrophobicity, turbidity, Free Sulfhydryl (SH) Content, particle size distribution, surface morphology, secondary conformation, thermal stability, solubility, emulsifying properties, and foaming characteristics were systematically evaluated. Structural modifications were characterized using Fourier-transform infrared spectroscopy (FTIR), fluorescence spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis and differential scanning calorimetry (DSC).
Results: The combined treatment significantly impacted the functional properties, including zeta potential and particle size of RPSPI-treated samples, enhancing stability compared to control samples. The structural data revealed important molecular modifications, including enhanced SH− content and reduced fluorescence intensity, suggesting that the structure partially unfolded. In addition, FTIR analysis combined with Amide I deconvolution demonstrated that MR and PEF treatments significantly altered the secondary structure composition of RPSPI, with changes in α-helix, β-sheet, β-turn, and random coil components. The combined MR-PEF treatment promoted greater protein conformational rearrangement, which was associated with improved dispersion behavior, and enhanced functional properties. SEM micrographs revealed significant changes and fragmentation, further supporting our findings. The XRD analysis revealed changes in crystalline structure and crystallinity, while DSC results demonstrated increased denaturation temperatures after treatment, indicating enhanced thermal stability of RPSPI. The combined treatments also had significant impacts on these structural changes, enhancing foaming capacity, solubility, and emulsifying properties and decreasing turbidity.
Conclusion: This study's findings add value to red pepper seed by-product and provide insight into novel processing methods for high-value plant protein components.
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BibTeX
@article{ali2026micronizationassisted,
title = {{Micronization-assisted pulsed electric field treatment on functional and structural modification of red pepper seed protein isolates}},
author = {Murtaza Ali and Muhammad Faisal Manzoor and Xin-An Zeng and Muhammad Talha Afraz and Isam A. Mohamed Ahmed},
journal = {Frontiers in Nutrition},
year = {2026},
month = oct,
doi = {10.3389/fnut.2026.1936132},
url = {https://doi.org/10.3389/fnut.2026.1936132},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Micronization-assisted pulsed electric field treatment on functional and structural modification of red pepper seed protein isolates
AU - Murtaza Ali
AU - Muhammad Faisal Manzoor
AU - Xin-An Zeng
AU - Muhammad Talha Afraz
AU - Isam A. Mohamed Ahmed
PY - 2026
DA - 2026/10/13
JO - Frontiers in Nutrition
DO - 10.3389/fnut.2026.1936132
UR - https://doi.org/10.3389/fnut.2026.1936132
AB - Background: Red pepper seeds are an underutilized source of plant proteins with functional potential, but their poor solubility and limited functionality restrict food applications. This study investigated the effects of micronization-assisted pulsed electric field (PEF) treatment on the structural, physicochemical, and functional properties of red pepper seed protein isolates (RPSPIs). Methods: RPSPIs were subjected to micronization pretreatment followed by PEF treatment under different electric field strengths and processing conditions. The effects of combined treatment on surface hydrophobicity, turbidity, Free Sulfhydryl (SH) Content, particle size distribution, surface morphology, secondary conformation, thermal stability, solubility, emulsifying properties, and foaming characteristics were systematically evaluated. Structural modifications were characterized using Fourier-transform infrared spectroscopy (FTIR), fluorescence spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis and differential scanning calorimetry (DSC). Results: The combined treatment significantly impacted the functional properties, including zeta potential and particle size of RPSPI-treated samples, enhancing stability compared to control samples. The structural data revealed important molecular modifications, including enhanced SH− content and reduced fluorescence intensity, suggesting that the structure partially unfolded. In addition, FTIR analysis combined with Amide I deconvolution demonstrated that MR and PEF treatments significantly altered the secondary structure composition of RPSPI, with changes in α-helix, β-sheet, β-turn, and random coil components. The combined MR-PEF treatment promoted greater protein conformational rearrangement, which was associated with improved dispersion behavior, and enhanced functional properties. SEM micrographs revealed significant changes and fragmentation, further supporting our findings. The XRD analysis revealed changes in crystalline structure and crystallinity, while DSC results demonstrated increased denaturation temperatures after treatment, indicating enhanced thermal stability of RPSPI. The combined treatments also had significant impacts on these structural changes, enhancing foaming capacity, solubility, and emulsifying properties and decreasing turbidity. Conclusion: This study's findings add value to red pepper seed by-product and provide insight into novel processing methods for high-value plant protein components.
SN - 2296-861X
ER -