Esterified Soy Proteins with Enhanced Antibacterial Properties for the Stabilization of Nano-Emulsions under Acidic Conditions
Soy protein isolate (SPI), including β-conglycinin (7S) and glycinin (11S), generally have low solubility under weakly acidic conditions due to the pH closed to their isoelectric points (pIs), which has limited their application in acidic emulsions. Changing protein pI through modification by esteri...
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MDPI AG
2023-03-01
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Online Access: | https://www.mdpi.com/1420-3049/28/7/3078 |
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author | Tingyu Wang Kehan Yi Yang Li Huan Wang Zhijun Fan Hua Jin Jing Xu |
author_facet | Tingyu Wang Kehan Yi Yang Li Huan Wang Zhijun Fan Hua Jin Jing Xu |
author_sort | Tingyu Wang |
collection | DOAJ |
description | Soy protein isolate (SPI), including β-conglycinin (7S) and glycinin (11S), generally have low solubility under weakly acidic conditions due to the pH closed to their isoelectric points (pIs), which has limited their application in acidic emulsions. Changing protein pI through modification by esterification could be a feasible way to solve this problem. This study aimed to obtain stable nano-emulsion with antibacterial properties under weakly acidic conditions by changing the pI of soy protein emulsifiers. Herein, the esterified soy protein isolate (MSPI), esterified β-conglycinin (M7S), and esterified glycinin (M11S) proteins were prepared. Then, pI, turbidimetric titration, Fourier transform infrared (FTIR) spectra, intrinsic fluorescence spectra, and emulsifying capacity of esterified protein were discussed. The droplet size, the ζ-potential, the stability, and the antibacterial properties of the esterified protein nano-emulsion were analyzed. The results revealed that the esterified proteins MSPI, M7S, and M11S had pIs, which were measured by ζ-potentials, as pH 10.4, 10.3, and 9.0, respectively, as compared to native proteins. All esterified-protein nano-emulsion samples showed a small mean particle size and good stability under weakly acidic conditions (pH 5.0), which was near the original pI of the soy protein. Moreover, the antibacterial experiments showed that the esterified protein-based nano-emulsion had an inhibitory effect on bacteria at pH 5.0. |
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issn | 1420-3049 |
language | English |
last_indexed | 2024-03-11T05:29:47Z |
publishDate | 2023-03-01 |
publisher | MDPI AG |
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spelling | doaj.art-7a38ef14765f41478c7083889313fbae2023-11-17T17:13:14ZengMDPI AGMolecules1420-30492023-03-01287307810.3390/molecules28073078Esterified Soy Proteins with Enhanced Antibacterial Properties for the Stabilization of Nano-Emulsions under Acidic ConditionsTingyu Wang0Kehan Yi1Yang Li2Huan Wang3Zhijun Fan4Hua Jin5Jing Xu6College of Arts and Sciences, Northeast Agricultural University, Harbin 150030, ChinaNational Research Center of Soybean Engineering and Technology, Harbin 150028, ChinaNational Research Center of Soybean Engineering and Technology, Harbin 150028, ChinaCollege of Food Science, Northeast Agricultural University, Harbin 150030, ChinaHeilongjiang Beidahuang Green and Healthy Food Co., Ltd., Jiamusi 154007, ChinaCollege of Arts and Sciences, Northeast Agricultural University, Harbin 150030, ChinaCollege of Arts and Sciences, Northeast Agricultural University, Harbin 150030, ChinaSoy protein isolate (SPI), including β-conglycinin (7S) and glycinin (11S), generally have low solubility under weakly acidic conditions due to the pH closed to their isoelectric points (pIs), which has limited their application in acidic emulsions. Changing protein pI through modification by esterification could be a feasible way to solve this problem. This study aimed to obtain stable nano-emulsion with antibacterial properties under weakly acidic conditions by changing the pI of soy protein emulsifiers. Herein, the esterified soy protein isolate (MSPI), esterified β-conglycinin (M7S), and esterified glycinin (M11S) proteins were prepared. Then, pI, turbidimetric titration, Fourier transform infrared (FTIR) spectra, intrinsic fluorescence spectra, and emulsifying capacity of esterified protein were discussed. The droplet size, the ζ-potential, the stability, and the antibacterial properties of the esterified protein nano-emulsion were analyzed. The results revealed that the esterified proteins MSPI, M7S, and M11S had pIs, which were measured by ζ-potentials, as pH 10.4, 10.3, and 9.0, respectively, as compared to native proteins. All esterified-protein nano-emulsion samples showed a small mean particle size and good stability under weakly acidic conditions (pH 5.0), which was near the original pI of the soy protein. Moreover, the antibacterial experiments showed that the esterified protein-based nano-emulsion had an inhibitory effect on bacteria at pH 5.0.https://www.mdpi.com/1420-3049/28/7/3078esterificationsoy proteinnano-emulsionacidicantibacterial |
spellingShingle | Tingyu Wang Kehan Yi Yang Li Huan Wang Zhijun Fan Hua Jin Jing Xu Esterified Soy Proteins with Enhanced Antibacterial Properties for the Stabilization of Nano-Emulsions under Acidic Conditions Molecules esterification soy protein nano-emulsion acidic antibacterial |
title | Esterified Soy Proteins with Enhanced Antibacterial Properties for the Stabilization of Nano-Emulsions under Acidic Conditions |
title_full | Esterified Soy Proteins with Enhanced Antibacterial Properties for the Stabilization of Nano-Emulsions under Acidic Conditions |
title_fullStr | Esterified Soy Proteins with Enhanced Antibacterial Properties for the Stabilization of Nano-Emulsions under Acidic Conditions |
title_full_unstemmed | Esterified Soy Proteins with Enhanced Antibacterial Properties for the Stabilization of Nano-Emulsions under Acidic Conditions |
title_short | Esterified Soy Proteins with Enhanced Antibacterial Properties for the Stabilization of Nano-Emulsions under Acidic Conditions |
title_sort | esterified soy proteins with enhanced antibacterial properties for the stabilization of nano emulsions under acidic conditions |
topic | esterification soy protein nano-emulsion acidic antibacterial |
url | https://www.mdpi.com/1420-3049/28/7/3078 |
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