Two nine-element sensor arrays, consisting of either three cationic poly(para-phenyleneethynylene)s (PPE) or the same PPEs complexed by cucurbituril[8] (CB[8]) at pH 3, 7, and 13 in water, discriminate 22 different teas and some of their small molecule components, including caffeine, theobromine and theophylline. Both arrays distinguish all of the black, green and oolong teas. The discrimination occurs by differential fluorescence modulation of the components of the sensor array and the treatment of the collected data by linear discriminant analysis. The signal is generated by either simple quenching (PPE only array) or the disruption of the PPE/CB[8] complex and quenching of the complex's or the PPEs' fluorescence through the polyphenolic colorants of the teas. Added amino acids, theobromine, theophylline, and caffeine give a fluorescence turn on of the PPE-CB[8] array, due to the disruption of the self-assembled complex, while for the PPE-alone tongue only caffeine, theobromine, and theophylline elicited useful fluorescence response. Both tongues discriminate different teas without any problem.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acssensors.7b00943 | DOI Listing |
Food Res Int
February 2025
Tea Refining and Innovation Key Laboratory of Sichuan Province, College of Horticulture, Sichuan Agricultural University, Chengdu 611130, Sichuan, PR China. Electronic address:
Ya'an Tibetan tea, a dark tea with a rich historical heritage, is typically processed using two primary piling fermentation methods: wet piling with rolled leaves (moisture content around 60%) and dry piling with sun-dried or baked green tea leaves (moisture content below 30%). This study employed sensory evaluation, targeted and non-targeted metabolomics, and fungal Internal Transcribed Spacer (ITS) sequencing to investigate changes in quality components and fungal composition in Tibetan tea processed by both wet and dry-piling methods. The results revealed that 3,7-Dimethyl-1,5,7-octatriene-3-ol and D-limonene were identified as key volatile metabolites contributing to the aroma variations between the dry and wet-piled teas.
View Article and Find Full Text PDFJ Chromatogr A
January 2025
College of Light Industry and Food Engineering, Nanjing Forestry University, Longpan Road 159, Nanjing 210037, China. Electronic address:
Storage duration significantly influences the aroma profile of raw Pu-erh tea. To comprehensively investigate the differences in the volatile compounds across various vintages of raw Pu-erh teas and achieve the rapid classification of tea vintages, volatile compounds of raw Pu-erh tea with different years (2020-2023) were analyzed using a combination of gas chromatography-ion mobility spectrometry (GC-IMS) and gas chromatography-mass spectrometry (GC-MS). The datasets obtained from both techniques were integrated through low-level and mid-level data fusion strategies.
View Article and Find Full Text PDFFoods
December 2024
Shaanxi Provincial Bioresources Key Laboratory, Shaanxi University of Technology, Hanzhong 723000, China.
Southern Shaanxi is one of China's high-quality congou black tea production areas. However, the differences in geography, cultivation, and management techniques and production processes lead to uneven qualities of southern Shaanxi congou black tea in different production areas. This study used sensory analysis combined with gas chromatography-ion mobility spectrometry (GC-IMS) to determine southern Shaanxi congou black teas' geographical origin and volatile fingerprints to prevent economic losses caused by fraudulent labeling.
View Article and Find Full Text PDFFood Res Int
January 2025
College of Food Science and Engineering, Jilin University, Changchun 130062, PR China. Electronic address:
Most reported sensor arrays for teas were based on the sensing of phenolic hydroxyl group on tea polyphenols. In this work, a novel sensor array was developed based on the simultaneous sensing of phenols and ketones, for the enhanced discrimination of tea polyphenols with/without ketone, and then for the efficient discrimination of raw Pu-erh teas from different origins and the counterfeit, combined with machine learning. This sensor array is consisting of four channels.
View Article and Find Full Text PDFJ Ethnopharmacol
January 2025
Traditional Chinese Medicine Processing Technology Innovation Centre of Hebei Province, College of Pharmacy, Hebei University of Chinese Medicine, Shijiazhuang, 050200, China; International Joint Research Centre on Resource Utilization and Quality Evaluation of Traditional Chinese Medicine of Hebei Province, Shijiazhuang, 050200, China. Electronic address:
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!