Composition of Volatile Compounds Generated from Simulated Thermal Reaction of L-Theanine with Monosaccharides

To investigate the potential of L-theanine (Thea) as an aroma precursor, the composition of volatile compounds generated from the thermal reaction between Thea and monosaccharides, simulating the Maillard reaction, was analyzed by gas chromatography-mass spectrometry (GC-MS). Thea reacted with four...

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Main Author: GUO Xiangyang, WAN Xiaochun
Format: Article
Language:English
Published: China Food Publishing Company 2025-07-01
Series:Shipin Kexue
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Online Access:https://www.spkx.net.cn/fileup/1002-6630/PDF/2025-46-13-020.pdf
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author GUO Xiangyang, WAN Xiaochun
author_facet GUO Xiangyang, WAN Xiaochun
author_sort GUO Xiangyang, WAN Xiaochun
collection DOAJ
description To investigate the potential of L-theanine (Thea) as an aroma precursor, the composition of volatile compounds generated from the thermal reaction between Thea and monosaccharides, simulating the Maillard reaction, was analyzed by gas chromatography-mass spectrometry (GC-MS). Thea reacted with four common monosaccharide in tea, D-glucose (Glc), D-galactose (Gal), D-arabinose (Arab) and D-xylose (Xyl) at 120 ℃ for 2 h, generating volatile compounds. The reaction with Glc and Gal generated larger numbers of volatile compounds (32 and 21, respectively), and 17 and 12 nitrogen-containing compounds were found in the reaction products, respectively, heterocyclic compounds with pyrrole and amide structures being the major ones, including four compounds contributing to roasted aroma, 4-ethyl-2-methylpyrrole, 4-ethyl-2,3-dimethyl-1H-pyrrole, 2-acetylpyrrole and N-ethyl succinimide. In contrast, only 6 and 9 volatile compounds were identified in the reaction products of Thea with Arab and Xyl, respectively. The reaction with Arab produced larger amounts of heterocyclic compounds with pyrrole structure such as 2,3-dimethyl-1H-pyrrole, responsible for roasted aroma, whereas the reaction with Xyl mainly produced heterocyclic compounds with furan structure. Additionally, Thea was transformed into volatile components when heated to 120 ℃. Among the identified volatile compounds, those with pyrimidine structure and alkane compounds were present in higher amounts. Furthermore, it was speculated that some volatile components might be formed by the Maillard reaction or the Strecker degradation. Principal component analysis (PCA) could effectively distinguish different thermal reactions, indicating that the reaction characteristics of Thea with different monosaccharides varied. This study not only provides data support for understanding the formation mechanism of tea aroma but also lays a theoretical foundation for the processing optimization and quality control of tea.
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publishDate 2025-07-01
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spelling doaj-art-efa5c6c2d62d49588057dcfc19a76e7d2025-08-20T03:51:08ZengChina Food Publishing CompanyShipin Kexue1002-66302025-07-01461321418010.7506/spkx1002-6630-20250108-055Composition of Volatile Compounds Generated from Simulated Thermal Reaction of L-Theanine with MonosaccharidesGUO Xiangyang, WAN Xiaochun0(1. College of Tea and Food Science, Xinyang Normal University, Xinyang 464000, China; 2. College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China; 3. National Key Laboratory for Tea Plant Germplasm Innovation and Resource Utilization, Anhui Agricultural University, Hefei 230036, China)To investigate the potential of L-theanine (Thea) as an aroma precursor, the composition of volatile compounds generated from the thermal reaction between Thea and monosaccharides, simulating the Maillard reaction, was analyzed by gas chromatography-mass spectrometry (GC-MS). Thea reacted with four common monosaccharide in tea, D-glucose (Glc), D-galactose (Gal), D-arabinose (Arab) and D-xylose (Xyl) at 120 ℃ for 2 h, generating volatile compounds. The reaction with Glc and Gal generated larger numbers of volatile compounds (32 and 21, respectively), and 17 and 12 nitrogen-containing compounds were found in the reaction products, respectively, heterocyclic compounds with pyrrole and amide structures being the major ones, including four compounds contributing to roasted aroma, 4-ethyl-2-methylpyrrole, 4-ethyl-2,3-dimethyl-1H-pyrrole, 2-acetylpyrrole and N-ethyl succinimide. In contrast, only 6 and 9 volatile compounds were identified in the reaction products of Thea with Arab and Xyl, respectively. The reaction with Arab produced larger amounts of heterocyclic compounds with pyrrole structure such as 2,3-dimethyl-1H-pyrrole, responsible for roasted aroma, whereas the reaction with Xyl mainly produced heterocyclic compounds with furan structure. Additionally, Thea was transformed into volatile components when heated to 120 ℃. Among the identified volatile compounds, those with pyrimidine structure and alkane compounds were present in higher amounts. Furthermore, it was speculated that some volatile components might be formed by the Maillard reaction or the Strecker degradation. Principal component analysis (PCA) could effectively distinguish different thermal reactions, indicating that the reaction characteristics of Thea with different monosaccharides varied. This study not only provides data support for understanding the formation mechanism of tea aroma but also lays a theoretical foundation for the processing optimization and quality control of tea.https://www.spkx.net.cn/fileup/1002-6630/PDF/2025-46-13-020.pdfl-theanine; tea monosaccharides; volatile compounds; maillard reaction; formation mechanism of tea aroma
spellingShingle GUO Xiangyang, WAN Xiaochun
Composition of Volatile Compounds Generated from Simulated Thermal Reaction of L-Theanine with Monosaccharides
Shipin Kexue
l-theanine; tea monosaccharides; volatile compounds; maillard reaction; formation mechanism of tea aroma
title Composition of Volatile Compounds Generated from Simulated Thermal Reaction of L-Theanine with Monosaccharides
title_full Composition of Volatile Compounds Generated from Simulated Thermal Reaction of L-Theanine with Monosaccharides
title_fullStr Composition of Volatile Compounds Generated from Simulated Thermal Reaction of L-Theanine with Monosaccharides
title_full_unstemmed Composition of Volatile Compounds Generated from Simulated Thermal Reaction of L-Theanine with Monosaccharides
title_short Composition of Volatile Compounds Generated from Simulated Thermal Reaction of L-Theanine with Monosaccharides
title_sort composition of volatile compounds generated from simulated thermal reaction of l theanine with monosaccharides
topic l-theanine; tea monosaccharides; volatile compounds; maillard reaction; formation mechanism of tea aroma
url https://www.spkx.net.cn/fileup/1002-6630/PDF/2025-46-13-020.pdf
work_keys_str_mv AT guoxiangyangwanxiaochun compositionofvolatilecompoundsgeneratedfromsimulatedthermalreactionofltheaninewithmonosaccharides