[Objective] This study aimed to test the effects of high-intensity pulsed electric field on the amino acid content in Pu’er tea leaves. [Method] The amino acid contents of fermented and unfermented the leaves of larg...[Objective] This study aimed to test the effects of high-intensity pulsed electric field on the amino acid content in Pu’er tea leaves. [Method] The amino acid contents of fermented and unfermented the leaves of large-leaf Pu’er tea variety produced in Yunnan Mengku, were measured before and after the treatment with high-intensity pulsed electric field （HPEF）. [Result] The difference of amino acid contents was notable between fermented and unfermented tea leaves produced in the same year. The amino acid content of unfermented tea leaves was larger than that in fermented tea leaves. The amino acid content in tea leaves decreased over time during storage. HPEF treatment under al the conditions improved the amino acid content in tea leaves. [Conclusion] This experiment provides theoretical foundation for the application of HPEF in processing of Pu’er tea leaves.展开更多
The rare earth elements contents (La, Ce, Pr, Nd, Sm) in 150 Pu er tea samples were analyzed by using inductively coupled plasma atomic emission spectroscopy (ICP-AES), to evaluate the safety of Pu er tea. Among the i...The rare earth elements contents (La, Ce, Pr, Nd, Sm) in 150 Pu er tea samples were analyzed by using inductively coupled plasma atomic emission spectroscopy (ICP-AES), to evaluate the safety of Pu er tea. Among the investigated rare earth elements (REEs), Ce was the highest (35% of the total REEs content) whose concentrations were found to be in the range of 0.11–1.39 mg/kg, whereas that of Sm in the range 0.01–0.21 mg/kg, showing minimum levels (5.2%). La was the second highest element (28%) found in Pu e...展开更多
As per conventional wisdom, scientists and the lay public differ in their epistemic abilities. Based on an analysis of a public debate on Pu'er tea, this paper emphasizes that there are differences between scienti...As per conventional wisdom, scientists and the lay public differ in their epistemic abilities. Based on an analysis of a public debate on Pu'er tea, this paper emphasizes that there are differences between scientists and the lay public in their epistemic perspectives, including differences in attention, problem definition, criteria for judgement and reasoning. These perspectives may differ in degree and may switch or combine. This difference may explain the failure of communication between scientists and the general public. Thus, the success of such communication depends on overcoming the perspective paradox.展开更多
The current situation of Pu'er tea in Yunnan was analyzed.The analysis result showed that the production output of Yunnan tea and the tea plantation area increased greatly when compared with the whole country,but ...The current situation of Pu'er tea in Yunnan was analyzed.The analysis result showed that the production output of Yunnan tea and the tea plantation area increased greatly when compared with the whole country,but the increase of Pu'er tea inclined to be stable.The restraining factors of Pu'er tea development were explored,and the corresponding countermeasures were put forward.It provided the basis for the sustainable development of Yunnan Pu'er tea.展开更多
Microorganisms play a significant role in the quality formation of raw Pu’er tea,and volatile compounds mainly contribute to the aroma quality.However,different de-enzyming methods on the quality of raw Pu’er tea ha...Microorganisms play a significant role in the quality formation of raw Pu’er tea,and volatile compounds mainly contribute to the aroma quality.However,different de-enzyming methods on the quality of raw Pu’er tea has not yet been reported.Microbiome and metabolomics were employed to comprehensively compare and analyze microbial community and volatile compounds in machine de-enzyming raw Pu’er tea(JS)and manual de-enzyming raw Pu’er tea(SS)in this study.High-throughput sequencing results showed that bacterial and fungal community compositions of JS and SS samples at phylum and genus levels were essentially identical,differed in relative abundance.A total of 65 and 71 volatile compounds were detected and characterized in JS and SS samples,respectively.Volatile components in JS and SS samples were mainly composed of alcohols,esters,aldehydes,alkanes,benzene and its derivatives,ketones,alkenes,phenols.A total of 88 differential volatile components between JS and SS samples were screened based on VIP>1 and p-value<0.05.Those results indicated that both microbial community composition and volatile compounds in raw Pu’er tea influenced by different de-enzyming methods.This work helps reveal the effect of different de-enzyming methods on the quality of raw Pu’er tea and provide a scientific reference basis for the improvement of raw Pu’er tea quality.展开更多
基金Supported by Scientific Research Fund from Department of Education of Yunnan Province(2012Z134C)~~
文摘[Objective] This study aimed to test the effects of high-intensity pulsed electric field on the amino acid content in Pu’er tea leaves. [Method] The amino acid contents of fermented and unfermented the leaves of large-leaf Pu’er tea variety produced in Yunnan Mengku, were measured before and after the treatment with high-intensity pulsed electric field （HPEF）. [Result] The difference of amino acid contents was notable between fermented and unfermented tea leaves produced in the same year. The amino acid content of unfermented tea leaves was larger than that in fermented tea leaves. The amino acid content in tea leaves decreased over time during storage. HPEF treatment under al the conditions improved the amino acid content in tea leaves. [Conclusion] This experiment provides theoretical foundation for the application of HPEF in processing of Pu’er tea leaves.
基金Project supported by the Foundation of National Key Technology R & D Program (2007BAD58B05-3)
文摘The rare earth elements contents (La, Ce, Pr, Nd, Sm) in 150 Pu er tea samples were analyzed by using inductively coupled plasma atomic emission spectroscopy (ICP-AES), to evaluate the safety of Pu er tea. Among the investigated rare earth elements (REEs), Ce was the highest (35% of the total REEs content) whose concentrations were found to be in the range of 0.11–1.39 mg/kg, whereas that of Sm in the range 0.01–0.21 mg/kg, showing minimum levels (5.2%). La was the second highest element (28%) found in Pu e...
文摘As per conventional wisdom, scientists and the lay public differ in their epistemic abilities. Based on an analysis of a public debate on Pu'er tea, this paper emphasizes that there are differences between scientists and the lay public in their epistemic perspectives, including differences in attention, problem definition, criteria for judgement and reasoning. These perspectives may differ in degree and may switch or combine. This difference may explain the failure of communication between scientists and the general public. Thus, the success of such communication depends on overcoming the perspective paradox.
基金Supported by the Earmarked Fund for Modern Agro-industry Technology Research System
文摘The current situation of Pu'er tea in Yunnan was analyzed.The analysis result showed that the production output of Yunnan tea and the tea plantation area increased greatly when compared with the whole country,but the increase of Pu'er tea inclined to be stable.The restraining factors of Pu'er tea development were explored,and the corresponding countermeasures were put forward.It provided the basis for the sustainable development of Yunnan Pu'er tea.
文摘Microorganisms play a significant role in the quality formation of raw Pu’er tea,and volatile compounds mainly contribute to the aroma quality.However,different de-enzyming methods on the quality of raw Pu’er tea has not yet been reported.Microbiome and metabolomics were employed to comprehensively compare and analyze microbial community and volatile compounds in machine de-enzyming raw Pu’er tea(JS)and manual de-enzyming raw Pu’er tea(SS)in this study.High-throughput sequencing results showed that bacterial and fungal community compositions of JS and SS samples at phylum and genus levels were essentially identical,differed in relative abundance.A total of 65 and 71 volatile compounds were detected and characterized in JS and SS samples,respectively.Volatile components in JS and SS samples were mainly composed of alcohols,esters,aldehydes,alkanes,benzene and its derivatives,ketones,alkenes,phenols.A total of 88 differential volatile components between JS and SS samples were screened based on VIP>1 and p-value<0.05.Those results indicated that both microbial community composition and volatile compounds in raw Pu’er tea influenced by different de-enzyming methods.This work helps reveal the effect of different de-enzyming methods on the quality of raw Pu’er tea and provide a scientific reference basis for the improvement of raw Pu’er tea quality.
