Natural Rubber/Hexagonal Mesoporous Silica Nanocomposites as Efficient Adsorbents for the Selective Adsorption of (−)-Epigallocatechin Gallate and Caffeine from Green Tea
(–)-Epigallocatechin gallate (EGCG) is a bioactive component of green tea that provides many health benefits. However, excessive intake of green tea may cause adverse effects of caffeine (CAF) since green tea (30–50 mg) has half the CAF content of coffee (80–100 mg). In this work, for enhancing the...
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MDPI AG
2023-08-01
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| Series: | Molecules |
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| author | Kamolwan Jermjun Rujeeluk Khumho Mookarin Thongoiam Satit Yousatit Toshiyuki Yokoi Chawalit Ngamcharussrivichai Sakdinun Nuntang |
| author_facet | Kamolwan Jermjun Rujeeluk Khumho Mookarin Thongoiam Satit Yousatit Toshiyuki Yokoi Chawalit Ngamcharussrivichai Sakdinun Nuntang |
| author_sort | Kamolwan Jermjun |
| collection | DOAJ |
| description | (–)-Epigallocatechin gallate (EGCG) is a bioactive component of green tea that provides many health benefits. However, excessive intake of green tea may cause adverse effects of caffeine (CAF) since green tea (30–50 mg) has half the CAF content of coffee (80–100 mg). In this work, for enhancing the health benefits of green tea, natural rubber/hexagonal mesoporous silica (NR/HMS) nanocomposites with tunable textural properties were synthesized using different amine template sizes and applied as selective adsorbents to separate EGCG and CAF from green tea. The resulting adsorbents exhibited a wormhole-like silica framework, high specific surface area (528–578 m<sup>2</sup> g<sup>−1</sup>), large pore volume (0.76–1.45 cm<sup>3</sup> g<sup>−1</sup>), and hydrophobicity. The NR/HMS materials adsorbed EGCG more than CAF; the selectivity coefficient of EGCG adsorption was 3.6 times that of CAF adsorption. The EGCG adsorption capacity of the NR/HMS series was correlated with their pore size and surface hydrophobicity. Adsorption behavior was well described by a pseudo-second-order kinetic model, indicating that adsorption involved H-bonding interactions between the silanol groups of the mesoporous silica surfaces and the hydroxyl groups of EGCG and the carbonyl group of CAF. As for desorption, EGCG was more easily removed than CAF from the NR/HMS surface using an aqueous solution of ethanol. Moreover, the NR/HMS materials could be reused for EGCG adsorption at least three times. The results suggest the potential use of NR/HMS nanocomposites as selective adsorbents for the enrichment of EGCG in green tea. In addition, it could be applied as an adsorbent in the filter to reduce the CAF content in green tea by up to 81.92%. |
| first_indexed | 2024-03-10T23:41:51Z |
| format | Article |
| id | doaj.art-c10b012764ea4ea2b1fa29ac70851bf5 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-10T23:41:51Z |
| publishDate | 2023-08-01 |
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| series | Molecules |
| spelling | doaj.art-c10b012764ea4ea2b1fa29ac70851bf52023-11-19T02:23:29ZengMDPI AGMolecules1420-30492023-08-012816601910.3390/molecules28166019Natural Rubber/Hexagonal Mesoporous Silica Nanocomposites as Efficient Adsorbents for the Selective Adsorption of (−)-Epigallocatechin Gallate and Caffeine from Green TeaKamolwan Jermjun0Rujeeluk Khumho1Mookarin Thongoiam2Satit Yousatit3Toshiyuki Yokoi4Chawalit Ngamcharussrivichai5Sakdinun Nuntang6Industrial Chemistry Innovation Program, Faculty of Science, Maejo University, Chiang Mai 50290, ThailandDepartment of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330, ThailandDepartment of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330, ThailandDepartment of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330, ThailandChemical Resources Laboratory, Tokyo Institute of Technology, Yokohama 226-8503, JapanDepartment of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330, ThailandIndustrial Chemistry Innovation Program, Faculty of Science, Maejo University, Chiang Mai 50290, Thailand(–)-Epigallocatechin gallate (EGCG) is a bioactive component of green tea that provides many health benefits. However, excessive intake of green tea may cause adverse effects of caffeine (CAF) since green tea (30–50 mg) has half the CAF content of coffee (80–100 mg). In this work, for enhancing the health benefits of green tea, natural rubber/hexagonal mesoporous silica (NR/HMS) nanocomposites with tunable textural properties were synthesized using different amine template sizes and applied as selective adsorbents to separate EGCG and CAF from green tea. The resulting adsorbents exhibited a wormhole-like silica framework, high specific surface area (528–578 m<sup>2</sup> g<sup>−1</sup>), large pore volume (0.76–1.45 cm<sup>3</sup> g<sup>−1</sup>), and hydrophobicity. The NR/HMS materials adsorbed EGCG more than CAF; the selectivity coefficient of EGCG adsorption was 3.6 times that of CAF adsorption. The EGCG adsorption capacity of the NR/HMS series was correlated with their pore size and surface hydrophobicity. Adsorption behavior was well described by a pseudo-second-order kinetic model, indicating that adsorption involved H-bonding interactions between the silanol groups of the mesoporous silica surfaces and the hydroxyl groups of EGCG and the carbonyl group of CAF. As for desorption, EGCG was more easily removed than CAF from the NR/HMS surface using an aqueous solution of ethanol. Moreover, the NR/HMS materials could be reused for EGCG adsorption at least three times. The results suggest the potential use of NR/HMS nanocomposites as selective adsorbents for the enrichment of EGCG in green tea. In addition, it could be applied as an adsorbent in the filter to reduce the CAF content in green tea by up to 81.92%.https://www.mdpi.com/1420-3049/28/16/6019natural rubberhexagonal mesoporous silicaadsorption(−)-epigallocatechincaffeine |
| spellingShingle | Kamolwan Jermjun Rujeeluk Khumho Mookarin Thongoiam Satit Yousatit Toshiyuki Yokoi Chawalit Ngamcharussrivichai Sakdinun Nuntang Natural Rubber/Hexagonal Mesoporous Silica Nanocomposites as Efficient Adsorbents for the Selective Adsorption of (−)-Epigallocatechin Gallate and Caffeine from Green Tea Molecules natural rubber hexagonal mesoporous silica adsorption (−)-epigallocatechin caffeine |
| title | Natural Rubber/Hexagonal Mesoporous Silica Nanocomposites as Efficient Adsorbents for the Selective Adsorption of (−)-Epigallocatechin Gallate and Caffeine from Green Tea |
| title_full | Natural Rubber/Hexagonal Mesoporous Silica Nanocomposites as Efficient Adsorbents for the Selective Adsorption of (−)-Epigallocatechin Gallate and Caffeine from Green Tea |
| title_fullStr | Natural Rubber/Hexagonal Mesoporous Silica Nanocomposites as Efficient Adsorbents for the Selective Adsorption of (−)-Epigallocatechin Gallate and Caffeine from Green Tea |
| title_full_unstemmed | Natural Rubber/Hexagonal Mesoporous Silica Nanocomposites as Efficient Adsorbents for the Selective Adsorption of (−)-Epigallocatechin Gallate and Caffeine from Green Tea |
| title_short | Natural Rubber/Hexagonal Mesoporous Silica Nanocomposites as Efficient Adsorbents for the Selective Adsorption of (−)-Epigallocatechin Gallate and Caffeine from Green Tea |
| title_sort | natural rubber hexagonal mesoporous silica nanocomposites as efficient adsorbents for the selective adsorption of epigallocatechin gallate and caffeine from green tea |
| topic | natural rubber hexagonal mesoporous silica adsorption (−)-epigallocatechin caffeine |
| url | https://www.mdpi.com/1420-3049/28/16/6019 |
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