Title: | Influence of fixation methods on the chestnut-like aroma of green tea and dynamics of key aroma substances |
Author(s): | Wang H; Hua J; Jiang Y; Yang Y; Wang J; Yuan H; |
Address: | "Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling South Road, Hangzhou, Zhejiang 310008, PR China. Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling South Road, Hangzhou, Zhejiang 310008, PR China. Electronic address: jiangyw@tricaas.com. Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling South Road, Hangzhou, Zhejiang 310008, PR China. Electronic address: 192168092@tricaas.com" |
DOI: | 10.1016/j.foodres.2020.109479 |
ISSN/ISBN: | 1873-7145 (Electronic) 0963-9969 (Linking) |
Abstract: | "Fixation is the key process to ensure green tea quality; however, the effect of various fixation methods on the formation of green tea with a chestnut-like aroma and the evolution of key volatile compounds has not been assessed to date. In this study, we compared four types of fixation methods for green tea: roller-hot air-steam, roller-hot air, roller-steam, and single roller. Infrared-assisted headspace solid-phase microextraction and gas chromatography-tandem dual mass spectrometry technology were used to detect the volatile compounds of green tea samples during processing. Partial least-squares discriminant analysis (PLS-DA), multiple experiment viewer (MEV), odor activity value (OAV), and least-significant difference analyzes were then applied to clarify the best fixation method for forming a chestnut-like aroma and associated compounds, and to explore the change law of key volatile compounds using different green tea fixation processes. One hundred and eighty-four volatile compounds were detected in the processed samples, with roller-hot air fixation found as the optimal method for generating an intense and long-lasting chestnut-like aroma and floral taste, based on sensory evaluation. The PLS-DA model clearly distinguished the four kinds of fixation samples and obtained 32 differential volatile compounds. Combining OAVs with screening by MEV analysis, 2,6,10,10-tetramethyl-1-oxaspiro [4.5] dec-6-ene, linalool, cedrol, 3-methyl-butanal, trans-beta-ionone, and tau-cadinol emerged as key differential volatile compounds between green teas with and without a chestnut-like aroma. The evolution of these six differential volatile compounds throughout the tea-making process confirmed that rolling-hot air coupling treatment is most conducive to produce a chestnut-like aroma, which is beneficial to form and transform 2,6,10,10-tetramethyl-1-oxaspiro[4.5] dec-6-ene, 3-methyl-butanal, and tau-cadinol with baking aromas and fruity substances. These results provide a theoretical basis and technical guidance for the precise and directional processing of high-quality green tea with a chestnut-like aroma" |
Keywords: | Gas Chromatography-Mass Spectrometry *Odorants/analysis Solid Phase Microextraction Tea *Volatile Organic Compounds/analysis Electromagnetic roller-hot air-steam triple fixation Gas chromatography-tandem mass spectrometry (GC-MS) Infrared-assisted headspa; |
Notes: | "MedlineWang, Huajie Hua, Jinjie Jiang, Yongwen Yang, Yanqin Wang, Jinjin Yuan, Haibo eng Research Support, Non-U.S. Gov't Canada 2020/08/28 Food Res Int. 2020 Oct; 136:109479. doi: 10.1016/j.foodres.2020.109479. Epub 2020 Jun 25" |