Characterization of N, O-heterocycles in green tea during the drying process and unraveling the formation mechanism. (September 2022)

• Record Type: Journal Article
• Authors: Yang, Yanqin; Xie, Jialing; Chen, Jiayu; Deng, Yuliang; Shen, Shuai; Hua, Jinjie; Wang, Jinjin; Zhu, Jiayi; Yuan, Haibo; Jiang, Yongwen
• Is Part Of: Food control. Volume 139(2022)
• Publication Date: 2022-09
• Subjects: Headspace solid-phase microextraction Arrow -- Gas chromatography-triple quadrupole-tandem mass spectrometry -- N, O-heterocycles -- Green tea -- Drying; Food -- Quality -- Periodicals; Food -- Analysis -- Periodicals; Food handling -- Periodicals; Food industry and trade -- Quality control -- Periodicals; Aliments -- Industrie et commerce -- Qualité -- Contrôle -- Périodiques; Aliments -- Qualité -- Périodiques; Aliments -- Analyse -- Périodiques; Hygiène alimentaire -- Périodiques; Food -- Analysis; Food handling; Food -- Quality; Periodicals; Electronic journals; 664.07
• DOI: 10.1016/j.foodcont.2022.109079
• Languages: English
• ISSNs: 0956-7135

Abstract

Abstract: N, O-Heterocycles play an important role in the characteristic flavor of green tea owing to their strong odors and low odor thresholds. In this study, a rapid and sensitive method was developed to determine seven N, O -heterocycles in green tea by using headspace solid-phase microextraction Arrow (HS-SPME-Arrow) coupled with gas chromatography-triple quadrupole-tandem mass spectrometry. The HS-SPME-Arrow extraction was performed using a Carbon WR SPME Arrow fiber. Good linear ranges (5–1000 ng/mL) were obtained, with correlation coefficients (R 2 ) higher than 0.99 for all target compounds. LODs and LOQs were in the range of 0.44–5.12 and 1.48–17.04 μg/kg, respectively. The recoveries of seven N, O -heterocycles were found to vary from 83.1% to 117.3%, with RSDs being lower than 10%. The dynamic changes of N, O -heterocycles during the drying process revealed that 25- and 40-min-long drying processes were key transition points. Furfural could be used as a key indicator compound for evaluating the extent of the drying. Moreover, furfural and 2-methylfuran revealed a significant positive correlation with proline ( p < 0.05). The possible formation mechanisms of N, O -heterocycles were further elaborated by simulated Maillard reactions. Our results provide a theoretical foundation for the improvement and directional regulation of aroma quality of green tea during manufacturing. Graphical abstract: Image 1 Highlights: A rapid and sensitive method was developed to determine seven N, O -heterocycles. Furfural could be used as a key indicator for evaluating the drying degree. Both 25- and 40-min-long drying processes were considered as key transition points. Drying methods had a significant effect on N, O -heterocycles ( p < 0.01).