Electronic nose has been applied in analysis of food products by monitoring their flavours.But it gives an overall response to a mixture of volatile components.In this work,multianalysis and chemometrics technique wer...Electronic nose has been applied in analysis of food products by monitoring their flavours.But it gives an overall response to a mixture of volatile components.In this work,multianalysis and chemometrics technique were employed to analyse the E-nose and GC-MS data of Longjing tea produced in different locations in Zhejiang province,China.A good discrimination of Longjing tea samples was obtained by E-nose according to the producing area,and a total of 38 compounds were commonly identified from the GC-MS data.Each individual volatile component was related to E-nose response using PLSR and the significance of each component was evaluated by the coefficient R2.Results indicated that isoamyl isovalerate,cis-3-hexenyl hexanoate,cadinene,phenylethylalcohol and linalool played an important role in response on E-nose sensors.It was possible to give a complementary information concerning the individual chemicals interacts with the sensors of E-nose instead of the total volatile components.展开更多
Long-term fertility cycle,low self-compatibility and short flowering period limited the tea breeding by conventional method.It is necessary to apply biotechnology,especially genetic transformation method,to obtain new...Long-term fertility cycle,low self-compatibility and short flowering period limited the tea breeding by conventional method.It is necessary to apply biotechnology,especially genetic transformation method,to obtain new mutants and to accelerate tea breeding.This paper reviews the status and progress in genetic transformation and related influencing factors.It has been noticed that tea genetic transformation has advantages in getting useful target mutants.The genetic transformation by Agrobacterium-mediated and gene gun methods are usually used.However,further research should be focused on improvement of plant regeneration.展开更多
Bifenthrin(BF) is an important type I synthetic fluorinated pyrethroid insecticide and acaricide.Previous investigations have indicated that the metabolisms of BF in human cells were through oxidative processes,and cy...Bifenthrin(BF) is an important type I synthetic fluorinated pyrethroid insecticide and acaricide.Previous investigations have indicated that the metabolisms of BF in human cells were through oxidative processes,and cytotoxicity was induced by the oxidative stress.In this study,the protective effects of EGCG,which is a major individual of green tea polyphenols,on the human embryonic lung fibroblast cell line HFL-I exposed to BF were investigated.The results showed that BF could induce oxidative stress leading to cytotoxicity in HFL-I cells.The pretreatment of EGCG at low concentrations significantly recovered the cell viability and morphology,inhibited excess generation of ROS,enhanced antioxidant enzyme activities and avoided loss of mitochondrial membrane potential.The results suggested that EGCG might eliminate the BF-induced damage in HFL-I cells.展开更多
Caffeine,theobromine and theophylline are the major purine alkaloids found in Camellia sinensis.Theacrine was detected in a special Chinese tea plant named kucha(Camellia kucha).With tracer experiments,the metabolism ...Caffeine,theobromine and theophylline are the major purine alkaloids found in Camellia sinensis.Theacrine was detected in a special Chinese tea plant named kucha(Camellia kucha).With tracer experiments,the metabolism pathway of these purine alkaloids has mostly been explored.The isolation and cloning of the genes encoding enzymes in the related pathway made it possible to develop methods to control caffeine level in tea products via transgenic technique.Further study on the kucha species would be helpful to obtain materials for processing naturally caffeine-less tea.However,there is still a long way to go in this direction such as sensory improvement of products prepared using leaves of kucha.展开更多
基金financial support from the China Agriculture (tea) Research System (CARS)Chinese Universities Scientific FundScientific Research Project of Zhejiang Education Department (Y201018805)
文摘Electronic nose has been applied in analysis of food products by monitoring their flavours.But it gives an overall response to a mixture of volatile components.In this work,multianalysis and chemometrics technique were employed to analyse the E-nose and GC-MS data of Longjing tea produced in different locations in Zhejiang province,China.A good discrimination of Longjing tea samples was obtained by E-nose according to the producing area,and a total of 38 compounds were commonly identified from the GC-MS data.Each individual volatile component was related to E-nose response using PLSR and the significance of each component was evaluated by the coefficient R2.Results indicated that isoamyl isovalerate,cis-3-hexenyl hexanoate,cadinene,phenylethylalcohol and linalool played an important role in response on E-nose sensors.It was possible to give a complementary information concerning the individual chemicals interacts with the sensors of E-nose instead of the total volatile components.
基金financially supported by the National Nature Science Foundation of China (Project No.31170645)Key Innovation Team of Zhejiang Province (No.2011R50024)
文摘Long-term fertility cycle,low self-compatibility and short flowering period limited the tea breeding by conventional method.It is necessary to apply biotechnology,especially genetic transformation method,to obtain new mutants and to accelerate tea breeding.This paper reviews the status and progress in genetic transformation and related influencing factors.It has been noticed that tea genetic transformation has advantages in getting useful target mutants.The genetic transformation by Agrobacterium-mediated and gene gun methods are usually used.However,further research should be focused on improvement of plant regeneration.
文摘Bifenthrin(BF) is an important type I synthetic fluorinated pyrethroid insecticide and acaricide.Previous investigations have indicated that the metabolisms of BF in human cells were through oxidative processes,and cytotoxicity was induced by the oxidative stress.In this study,the protective effects of EGCG,which is a major individual of green tea polyphenols,on the human embryonic lung fibroblast cell line HFL-I exposed to BF were investigated.The results showed that BF could induce oxidative stress leading to cytotoxicity in HFL-I cells.The pretreatment of EGCG at low concentrations significantly recovered the cell viability and morphology,inhibited excess generation of ROS,enhanced antioxidant enzyme activities and avoided loss of mitochondrial membrane potential.The results suggested that EGCG might eliminate the BF-induced damage in HFL-I cells.
基金financially supported by the National Nature Science Foundation of China (Project No.31170645,30900970)
文摘Caffeine,theobromine and theophylline are the major purine alkaloids found in Camellia sinensis.Theacrine was detected in a special Chinese tea plant named kucha(Camellia kucha).With tracer experiments,the metabolism pathway of these purine alkaloids has mostly been explored.The isolation and cloning of the genes encoding enzymes in the related pathway made it possible to develop methods to control caffeine level in tea products via transgenic technique.Further study on the kucha species would be helpful to obtain materials for processing naturally caffeine-less tea.However,there is still a long way to go in this direction such as sensory improvement of products prepared using leaves of kucha.
