| Summary: | 碩士 === 國立屏東科技大學 === 熱帶農業暨國際合作系所 === 95 === Investigations were conducted to analyze the volatile and non-volatile components and their characteristics in Toona sinensis Roemor leaves in Taitung. Non-volatile components were analyzed and identified by using High Performance Liquid Chromatography (HPLC) and HPLC-MS. Attempts were made to study the effects of fermentation in the content of the main phenolic acid components from different plant parts、including young leaves of T. sinensis from Taitung and Changhua. The volatile components in the young and old leaves of T. sinensis were analyzed and identified by using gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS). The changes of the non-volatile components in the fermented T. sinensis young leaves were also studied.The results demonstrated that gallic acid、methyl gallate and 5GG (1,2,3,4,6-penta-O-galloyl-beta-D-glucose) were isolated and identified from T. sinensis leaves. Based on the HPLC analysis、we found that the quantity of the components of gallic acid、methyl gallate and 5GG was similar in young and old leaves 、but different in the rest of plant parts. The components in different species were also different. The main phenolic acid components of T. sinensis leaves in Taitung was methyl gallate and 5GG、while that of T. sinensis leaves in Changhua was gallic acid. After fermentation、the main component of T. sinensis both from Taitung and Changhua was gallic acid. The amount of methyl gallate and 5GG decreased、while the amount of gallic acid increased、in the fermented T. sinensis leaves. It was likely that methyl gallate and 5GG degraded during the process of fermentation and formed gallic acid、resulting in further increase of gallic acid. Changes in the concentration of main phenolic acid compounds in processing T. sinensis into tea bag and pickle generated a similar result to that of fermenting T. sinensis leaves. The fact that the composition of T. sinensis leaf powder was similar to that of old T. sinensis leaves、indicated the thermal inhibitation of the hydrolization of methyl gallate and 5GG. This showed the likelihood no fermentation was taking place in the process. The percentage of the volatile components emitted from T. sinensis young and old leaves was similar on the base of GC-MS analysis. Among those identified、young leaves were characterized by the presence of dimethyl sulfide and carbon disulfide. The increase of dimethyl sulfide and carbon disulfide during the process of fermentation was quantified. During the fermentation of T. sinensis、the thermal reaction、which converts sulfides and aldehyds to thiophens、was found to be involved in the formation of meaty compounds、thus、enhancing the flavor of fermented T. sinensis leaves.
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