Influence of Different pH Values on Gels Produced from Tea Polyphenols and Low Acyl Gellan Gum
To explore the influence of pH values on the properties of a compound system containing tea polyphenols (TPs) and low acyl gellan gum (LGG), the color, texture characteristics, rheological properties, water holding capacity (WHC), and microstructure of the compound system were measured. The results...
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| Format: | Article |
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MDPI AG
2023-04-01
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| Series: | Gels |
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| Online Access: | https://www.mdpi.com/2310-2861/9/5/368 |
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| author | Fangyan Zhang Xiangcun Wang Na Guo Huanhuan Dai Yimei Wang Yiwei Sun Guilan Zhu |
| author_facet | Fangyan Zhang Xiangcun Wang Na Guo Huanhuan Dai Yimei Wang Yiwei Sun Guilan Zhu |
| author_sort | Fangyan Zhang |
| collection | DOAJ |
| description | To explore the influence of pH values on the properties of a compound system containing tea polyphenols (TPs) and low acyl gellan gum (LGG), the color, texture characteristics, rheological properties, water holding capacity (WHC), and microstructure of the compound system were measured. The results showed that the pH value noticeably affects the color and WHC of compound gels. Gels from pH 3 to 5 were yellow, gels from pH 6 to 7 were light brown, and gels from pH 8 to 9 were dark brown. The hardness decreased and the springiness increased with an increase in pH. The steady shear results showed that the viscosity of the compound gel solutions with different pH values decreased with increasing shear rates, indicating that all of the compound gel solutions were pseudoplastic fluids. The dynamic frequency results showed that the <i>G</i>′ and <i>G</i>″ of the compound gel solutions gradually decreased with increasing pH and that <i>G</i>′ was higher than <i>G</i>″. No phase transition occurred in the gel state under heating or cooling conditions at pH 3, indicating that the pH 3 compound gel solution was elastic. The WHC of the pH 3 compound gel was only 79.97% but the WHC of compound gels pH 6 and pH 7 was almost 100%. The network structure of the gels was dense and stable under acidic conditions. The electrostatic repulsion between the carboxyl groups was shielded by H<sup>+</sup> with increasing acidity. The three-dimensional network structure was easily formed by an increase in the interactions of the hydrogen bonds. |
| first_indexed | 2024-03-11T03:42:59Z |
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| id | doaj.art-c768eee3de1c4665ae452ec8fd96c60a |
| institution | Directory Open Access Journal |
| issn | 2310-2861 |
| language | English |
| last_indexed | 2024-03-11T03:42:59Z |
| publishDate | 2023-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Gels |
| spelling | doaj.art-c768eee3de1c4665ae452ec8fd96c60a2023-11-18T01:27:33ZengMDPI AGGels2310-28612023-04-019536810.3390/gels9050368Influence of Different pH Values on Gels Produced from Tea Polyphenols and Low Acyl Gellan GumFangyan Zhang0Xiangcun Wang1Na Guo2Huanhuan Dai3Yimei Wang4Yiwei Sun5Guilan Zhu6Department of Biological and Food Engineering, Hefei Normal University, Lian Hua Road, Hefei 230601, ChinaDepartment of Biological and Food Engineering, Hefei Normal University, Lian Hua Road, Hefei 230601, ChinaDepartment of Biological and Food Engineering, Hefei Normal University, Lian Hua Road, Hefei 230601, ChinaDepartment of Biological and Food Engineering, Hefei Normal University, Lian Hua Road, Hefei 230601, ChinaDepartment of Biological and Food Engineering, Hefei Normal University, Lian Hua Road, Hefei 230601, ChinaDepartment of Biological and Food Engineering, Hefei Normal University, Lian Hua Road, Hefei 230601, ChinaDepartment of Biological and Food Engineering, Hefei Normal University, Lian Hua Road, Hefei 230601, ChinaTo explore the influence of pH values on the properties of a compound system containing tea polyphenols (TPs) and low acyl gellan gum (LGG), the color, texture characteristics, rheological properties, water holding capacity (WHC), and microstructure of the compound system were measured. The results showed that the pH value noticeably affects the color and WHC of compound gels. Gels from pH 3 to 5 were yellow, gels from pH 6 to 7 were light brown, and gels from pH 8 to 9 were dark brown. The hardness decreased and the springiness increased with an increase in pH. The steady shear results showed that the viscosity of the compound gel solutions with different pH values decreased with increasing shear rates, indicating that all of the compound gel solutions were pseudoplastic fluids. The dynamic frequency results showed that the <i>G</i>′ and <i>G</i>″ of the compound gel solutions gradually decreased with increasing pH and that <i>G</i>′ was higher than <i>G</i>″. No phase transition occurred in the gel state under heating or cooling conditions at pH 3, indicating that the pH 3 compound gel solution was elastic. The WHC of the pH 3 compound gel was only 79.97% but the WHC of compound gels pH 6 and pH 7 was almost 100%. The network structure of the gels was dense and stable under acidic conditions. The electrostatic repulsion between the carboxyl groups was shielded by H<sup>+</sup> with increasing acidity. The three-dimensional network structure was easily formed by an increase in the interactions of the hydrogen bonds.https://www.mdpi.com/2310-2861/9/5/368tea polyphenolslow acyl gellan gumpH |
| spellingShingle | Fangyan Zhang Xiangcun Wang Na Guo Huanhuan Dai Yimei Wang Yiwei Sun Guilan Zhu Influence of Different pH Values on Gels Produced from Tea Polyphenols and Low Acyl Gellan Gum Gels tea polyphenols low acyl gellan gum pH |
| title | Influence of Different pH Values on Gels Produced from Tea Polyphenols and Low Acyl Gellan Gum |
| title_full | Influence of Different pH Values on Gels Produced from Tea Polyphenols and Low Acyl Gellan Gum |
| title_fullStr | Influence of Different pH Values on Gels Produced from Tea Polyphenols and Low Acyl Gellan Gum |
| title_full_unstemmed | Influence of Different pH Values on Gels Produced from Tea Polyphenols and Low Acyl Gellan Gum |
| title_short | Influence of Different pH Values on Gels Produced from Tea Polyphenols and Low Acyl Gellan Gum |
| title_sort | influence of different ph values on gels produced from tea polyphenols and low acyl gellan gum |
| topic | tea polyphenols low acyl gellan gum pH |
| url | https://www.mdpi.com/2310-2861/9/5/368 |
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