Foods
·
2024
·Vol. 13
·期 9
·1338
·
IF 4.7
Ruimin Teng,Cun Ao,Haitao Huang,Daliang Shi,Yuxiao Mao,Xuxia Zheng,Yun Zhao
Longjing tea is favored by consumers due to its refreshing and delicate aroma, as well as its fresh and sweet flavor. In order to study the processing technology of Longjing tea with ‘Baiye 1’ tea varieties, solid phase microextraction and gas chromatography–mass spectrometry were used to analyze the volatile components of Longjing tea in different process stages. The results revealed the identification of 275 aroma metabolites in the processing samples of Longjing tea. The sensory evaluation and principal component analysis revealed that the leaves of fresh (XY) and spreading (TF) were different from the leaves of first panning (YQ), second panning (EQ), final panning (HG), and fragrance enhancing (TX). The relative contents of geraniol (1199.95 and 1134.51), linalool (745.93 and 793.98), methyl salicylate (485.22 and 314.67), phenylethyl alcohol (280.14 and 393.98), 2-methylfuran (872.28 and 517.96), 2-butenal (56.01 and 154.60), and 2-hexenal (46.22 and 42.24), refreshing and floral substances in the XY and TF stages, were higher than other stages. The aroma contents of 2-methylfuran, furfural, 2-methyl-1-penten-3-one, 3-hexen-2-one, dodecane, hexanoyl hexanoate, 2,5-dimethyl-pyrazine, and methyl-pyrazine were found to be significantly positively correlated with the intensity of chestnut aroma. In conclusion, this study contributes to a better understanding of the composition and formation mechanism of chestnut-like aroma and provides new insights into the processing technology to improve the quality of albino green tea.
研究领域:
食品科学
·
植物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Heliyon
·
2023
·
IF 4
Xiao-Lan Yu,Jia Li,Yanqing Yang,Jiayi Zhu,Haibo Yuan,Yongwen Jiang
In this study, four kinds of Longjing tea, the famous flat green tea and the protected geographical indication product in China, were used to explore the quality difference of the same green tea due to the cultivar, geographic origin, and storage time under the premise of consistent picking conditions and processing technology using the widely targeted metabolomics. Results showed that 483 flavonoid metabolites with 10 subgroups of flavonoids were screened and 118 differential flavonoid metabolites were identified. The number and subgroups of differential flavonoid metabolites produced by different cultivars of Longjing tea were the largest, followed by storage time, and third by the geographic origin. Glycosidification and methylation or methoxylation were the main structural modifications of differential flavonoid metabolites. This study has enriched the understanding of the effects of the cultivar, the geographic origin, and the storage time on the flavonoid metabolic profiles of Longjing tea, and provided worthy information for the traceability of green tea.
研究领域:
食品科学
·
代谢组学
·
农业化学
✓ 已验证
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2016
·
IF 3.299
Yin Zhu,Hai-Peng Lv,Wei-Dong Dai,Li Guo,Jun-Feng Tan,Yue Zhang,Fang-Lin Yu,Chen-Yang Shao,Qun-Hua Peng,Zhi Lin
Aroma is one of the most important determinants of tea quality; thus, the precise characterization of the chemical composition of tea aroma is of significant value. In this study, aroma components of the most famous Chinese green tea, Xihu Longjing tea, were first systematically analyzed using comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOFMS) combined with simultaneous distillation extraction (SDE). 478 volatile compounds were identified as common constituents of fifty-five Xihu Longjing tea samples based on standard mass spectra in available databases, retention times, retention indices, structured chromatograms and standards. Subsequently, the aroma qualities of Xihu Longjing tea samples were discriminated by sensory evaluation combined with multivariate analysis. The study results indicated that 37 compounds were positively correlated with aroma quality, and 65 compounds were negatively correlated with aroma quality. The above compounds with various odor characteristics were considered as the key components to affect the aroma quality of Xihu Longjing tea.
研究领域:
食品科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2020
·
IF 4.006
Hui-Wen Gu,Xiao-Li Yin,Ying-Xiang Ma,Jing Wang,Fan Yang,Weiqing Sun,Baomiao Ding,Ying Chen,Zhi Liu
A new chemometrics-assisted high performance liquid chromatography-diode array detection (HPLC-DAD) method was developed to rapidly quantify ten major components in nine Xihu Longjing tea samples. This new strategy proved to be a useful tool for handling the co-eluted problems during chromatographic analysis and enabled the quantification of ten major components in tea samples within only 10 min. The average recoveries of these analytes in tea samples ranged from 100.0% to 112.7% except (−)-epigallocatechin gallate (EGCG). The relative standard deviations of intra- and inter-day assays were in the range of 0.14%–5.09% for all the ten analytes. Furthermore, the quantitative results were used as input variables to perform principal component analysis (PCA) and hierarchical cluster analysis (HCA) for differentiating tea grades. Results demonstrated that the nine different grades of Xihu Longjing tea samples were successfully divided into three categories. This study showed that it is possible to perform tea grades differentiation according to the contents of major components using chemometric pattern recognition methods.
研究领域:
食品科学
·
分析化学
✓ 已验证
DOI
高影响因子
FOOD CHEMISTRY
·
2024
·
IF 8.5
Hongling Wang,Xianghui Qi,Song Gao,Guoshi Kan,Lkhagvasuren Damdindorj,Yingfeng An,Fuping Lu
Herein, a novel multifunctional enzyme β-glucosidase/xylanase/feruloyl esterase (GXF) was constructed by fusion of β-glucosidase and bifunctional xylanase/feruloyl esterase. The activities of β-glucosidase, xylanase, feruloyl esterase and acetyl xylan esterase displayed by GXF were 67.18 %, 49.54 %, 38.92 % and 23.54 %, respectively, higher than that of the corresponding single functional enzymes. Moreover, the GXF performed better in enhancing aroma and quality of Longjing tea than the single functional enzymes and their mixtures. After treatment with GXF , the grassy and floral odors of tea infusion were significantly improved. Moreover, GXF treatment could improve concentrations of flavonoid aglycones of myricetin, kaempferol and quercetin by 68.1-, 81.42- and 77.39-fold, respectively. In addition, GXF could accelerate the release of reducing sugars, ferulic acid and xylo -oligosaccharides by 9.48-, 8.25- and 4.11-fold, respectively. This multifunctional enzyme may have potential applications in other fields such as food production and biomass degradation.
研究领域:
酶学
·
食品科学
·
茶叶技术
·
生物技术
✓ 已验证
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2023
·
IF 8.8
Yanyan Cao,Chuangsheng Huang,Yating Guo,Yingxin Xu,Shuying Gong,Qiang Chu,Ping Chen
Longjing tea is renowned for its fresh aroma and high value. However, during storage, the emergence of an off-flavor known as “stale odor” can significantly impact the flavor quality and economic benefits of Longjing tea. Yet, the specific volatiles responsible for this stale odor in Longjing tea remain unknown. In this study, Longjing tea samples with varying degrees of stale odor intensity were analyzed using simultaneous distillation extraction coupled with gas chromatography-mass spectrometry (SDE-GC–MS). Through odor activity value (OAV) and fractional omission testing, hexanoic acid and trans -2-nonenal were identified as the primary contributors to the stale odor. Moreover, the concentration of hexanoic acid was found to be valuable in predicting the intensity of the stale odor in Longjing tea. The oxidative degradation of linoleic acid was proved as the generation pathway of stale odor in Longjing tea. These findings provide essential theoretical principles for Longjing tea production and preservation.
研究领域:
食品科学
·
农业化学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）