Study On The Effect Of Processing Technology On The Chemical Composition And AGEs Inhibitory Activity Of Shi Liang Cha

Shi Liang Cha,a kind of herbal tea processed from the leaves of Chimonanthus salicifolius S.Y.Hu,is a traditional healthy beverage of Chinese She ethnic group more than hundreds of years.It can be used for both medicine and food.Shi Liang Cha has many functions,such as invigorate the spleen,relieve diarrhea,clearing away heat and toxic material.Its unique efficiency is inseparable from chemical composition.In this paper,the processes of yellow tea and black tea of Shi Liang Cha are researched along with the traditional technology of green tea.The main chemical constituents of Shi Liang Cha products with different processes and the leaves of C.salicifolius were determined by gas chromatography-mass spectrometry(GC-MS)and high performance liquid chromatography-mass spectrometry(HPLC-MS).The content change and mechanism of the main components were also studied.The research result may usful to the development of new kinds of Shi Liang Cha products and quality control.In recent years,researchers have found that flavonoids and polyphenols can effectively inhibit the formation of advanced glycation end products(AGEs).Shi Liang Cha is rich in flavonoids and polyphenols.So,the inhibitory effect on AGEs of Shi Liang Cha samples and its main active ingredients were determined by BSA-glucose model.The research focuses on the change of main components of Shi Liang Cha samples and the inhibition on AGEs.The results are as follows:1.GC-MS was used to analyze the volatile components of 8 samples(the leaf of C.salicifolius and 7 Shi Liang Cha products with different processes),and 36 aroma compounds were identified.Terpenoids are the main components.The type and content of volatile components have a great change in the process.The content of low boiling point volatile substances decreased,while the content of?-pinene,?-myrcene,D-limonene,eucalyptus oil and(1S)-6,6-dimethyl-2-methylenebicyclo[3.1.1]heptane increased in Shi Liang Cha products.2.Twelve main non-volative components were determined from the water and alcohol extracts of 8 samples by HPLC-MS.Among them,8 components are identified as scopoletin,rutin,isoquercitrin,astragalin,kaempferol-3-O-rutinoside,quercitin,quercetin and kaempferol by the comparison of authoritative standards.The influence of the processing technology on the above 8 main chemical components and the mechanism are also analyzed.The main component of the leaf of C.salicifolius,green tea(1~#and 2~#sample)and yellow tea(6~#and 7~#sample)is kaempferol-3-O-rutinoside.The main ingredients in black tea(3~#,4~#,and 5~#sample)are quercetin and kaempferol.The main reason of these different is that glycosides are decomposed and decreased continously during the fermentation of black tea.3.The inhibitory effect of water and ethanol extracts of 8 samples on AGEs fluorescent products was determined by BSA-glucose model.The inhibition rate of Shi Liang Cha products was higher than that of the leaves of C.salicifolius.The water extract of yellow tea had the best inhibition,followed by green tea and black tea.The activity of ethanol extract was better than that of water extract.The 3~#sample had the highest inhibition rate.The inhibitory effect on N~?-carboxymethyllysine(CML),non-fluorescent products of AGEs,was detected by HPLC-MS method.The water extract of the leaves and 2~#sample,the ethanol extract of 6~#sample had significant inhibitory effect on CML.4.Four flavonoids were isolated,purified and identified from sample 6~#,and identified as kaempferol,kaempferol-3-O-rutinoside,astragalin,and rutin.The AGEs inhibitory activities of the four compounds were also tested.The four compounds all had good inhibitory effects on the AGEs fluorescent products.Kaempferol and kaempferol-3-O-rutinoside had better inhibitory effect on CML.