| Cyclocarya paliurus(Batal.)Ijinskaja,a rare tree endemic to China,of which roots,branches and leaves can be used as medicine,are mainly distributed in mountainous areas at altitudes of 420-2500 m in some southern provinces of China.The geographical distribution of the tree is influenced by different growing environments and climatic differences,resulting in differences in the chemical composition of Cyclocarya paliurus leaves.In addition,the leaves can be made into tea or brewed directly after sun-dring,and are popular with consumers,especially in some areas of southern China where it is an ancient tradition to brew the dried leaves in hot water.Cold-brewing tea has gradually become a fashionable beverage in recent years due to its ease of handling and ability to reduce heat loss during the brewing process.In this experiment,GC-MS and UPLC-QTOF-MS techniques were selected to analyses the chemical composition and differences from different altitudinal sources of Cycocarya paliurus leaves.The data were subjected to multivariate statistical analysis and a classification model was constructed so as to establish a new method for the altitudinal traceability of Cycocarya paliurus leaves.In addition,a nontargeted metabolomics approach was used to study the effects of different brewing methods on the lysates of Cycocarya paliurus leaves.Finally,a bagged tea factory for Cycocarya paliurus leaves was designed and an overview of the process and project investment was provided.The main research and findings of this thesis are summarised as follows:Chapter 1: Details of the recent studies on various chemical constituents and their activities of Cycocarya paliurus leaves including flavonoids,phenolic acids,triterpenoids and polysaccharides.It was found that the leaves of Cycocarya paliurus from different geographical sources or growth cycles exhibited differentiation in polysaccharide,terpenoid and phenolic acid contents.Besides,the process of metabolomics is briefly introduced,which includes sample collection and preparation,metabolite isolation and detection and data analysis and metabolite identification.The application of metabolomics in the traceability of plant-based foods is described from the perspective of experimental process.Chapter 2: The experiment was based on head space-solid phase microextraction coupled with gas chromatography triple quadrupole tandem mass spectrometry(HS-SPME-GC-MS)technique to analyze the volatile components of Cycocarya paliurus leaves at different altitudes(200-1000 m)and explore the differences in volatile components among different clusters.The results showed that,based on the principle of VIP > 1.0,a total of 16 key differential compounds were screened,namely ?-Myrcene,2,4-Heptadienal,Nonanal,Decanal,Ylangene,Copaene,?-Bourbonene,Caryophyllene,Geranylacetone,?-Selinene,?-Cadinene,?-Calacorene,Caryophyllene oxide,Hexahydrofarnesyl acetone,Methyl palmitate,Manoyl oxide.Chapter 3: Experiments were conducted to investigate the differences in the non-volatile components of Cycocarya paliurus leaves from different altitudes(200-1000 m)by using ultra performance liquid chromatography tandem time of flight mass spectrometry(UPLC-QTOF-MS)technique.On the one hand,the 400 m altitude source of Cycocarya paliurus leaves had higher total phenolic(117.20±2.10 mg GAE/g)and total flavonoid(0.91±0.06 mg RE/g)contents,significantly higher than samples from other altitude environments(P < 0.05).On the other hand,15 signature compounds were selected by calculating the VIP and P-values for each compound and could be used for DD-SIMCA and ROC model discrimination.The results suggest that non-targeted metabolomics based on UPLC-QTOF-MS may provide a suitable method for the identification of Cycocarya paliurus leaves at different altitude environments.Chapter 4: A non-targeted metabolomics approach based on UPLC-QTOF-MS was used to compare the differences in dissolution between the three brewing methods of Cycocarya paliurus leaves.On the one hand,cold-brewing,as a specific method,promoted the release or dissolution of certain active substances,which contained the highest levels of ferulic acid,salicylic acid,p-coumaric acid and gallic acid among the 15 differential compounds identified.On the other hand,the boilbrewing or steep-brewing method had a positive effect on the release or dissolution of flavonoids.The present study provides a basis for the application of cold-brewing method in the application of Cycocarya paliurus leaves,which promotes the development of herbal teas based on Cycocarya paliurus leaves as raw material.Chapter 5: The factory production of Cycocarya paliurus tea bags is described,and the production process,the equipment required for the selection process and the estimated annual profit are designed.Combining objective conditions and production reality,the feasibility of the factory siting in Huang'o Township,Xiushui County was analyzed,and the overall layout of the factory was preliminarily planned with the production equipment models and specifications.In addition,combined with the actual production requirements and product value,the costs of raw material components,utilities costs and labor costs were estimated,and the payback period was estimated by integrating production costs,preliminary investment costs and profits,which is expected to be profitable after 5 years.The above work lays the theoretical foundation for the construction of Cycocarya paliurus tea bag factory. |
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