Font Size: a A A

Study On The Changes Of Main Quality Components And Its Influence Factors During Green Tea Storage

Posted on:2009-01-22Degree:MasterType:Thesis
Country:ChinaCandidate:F CuiFull Text:PDF
GTID:2121360242494378Subject:Tea
Abstract/Summary:PDF Full Text Request
In recent years, there were many studies on Green tea preservations, and people thought that tea will keep fresh if stored in low temperature, no-light, dry condition. On the contrary, there are few researches about how to speedup changes of quality components in storage. The traditional export tea produce need inclusion of new green tea have some chang before export. But until today, we do not know how accelerated quality change during tea storage,and what the variation of quality components is. The purpose of this paper is to discuss variational regulation of Tea polyphenols, amino acid and coffine in storage. And also discuss the effect of different temperature, different humidity, different water content and different time on tea quality. We want to find out a best way to speedup change of tea quality to smooth the way for tea matching and export.1. Tea is storaged in different Treatment Conditions,there is a great change of tea inclusion 4 days later.2. Tea is storaged in different Treatment Conditions, the content of Tea polyphenols and amino acid have the fluctuation change law.3. Tea is storaged in different Treatment Conditions, the content of Catechins and coffine have a decline trend.4. In low humidity,there is a greater inclusion change range in 50℃than in 40℃;In first 12 days, there has a large decreasing amount of coffine in 50℃,and then the decrease range in 40℃more than 50℃.In high humidity, 50℃is more prominence than 40℃and 70℃to influence Tea polyphenols, amino acid and coffine.5. In the same temperature, low humidity is more prominence than high humidity to influence Tea polyphenols and amino acid. In 40℃, The extent is 0~7.2% and -9.4%~12.2%,but the extent is 0~4.06% and -8.4%~8.8% in high humidity. In 50℃,low humidity is more prominence than high humidity to influence Tea polyphenols, Catechins and amino acid. The extent of Tea polyphenols and amino acid is -5.9%~13.8% and -13.9%~6.8%.But the extent is -7.5%~6.6% and -8.15%~8%;In 40℃, High humidity is more prominence than low humidity to influence Catechins and coffine.,Green tea was treatmented in high and low humidity 4 days later, Catechins content less 14.57% and 8.8% than CK in the same time. In 50℃, Catechins decreased by 35% in low humidity ,by 29% in high humidity. High humidity is more prominence than low humidity to influence coffine,The content is decline by 24.6% until 45days.6. The infusion color of tea liquor was measured by color difference instrument. The results shows that. In the certain time and condition, sensory evaluation of light is good if there is a highΔL,but it will has new change if exceed a certain time. We can use color difference instrument to judgement infusion color of tea liquor,but it need future study if be use in pactical.Meanwhile, aim at the factory production, Roasted Green Tea be processed in short time under specific condition .And then pick them out and store in room temperature. Compare the variation of Tea polyphenols, Catechins ,amino acid and coffine of tea storing in different conditions. And discuss effect of temperature, humidity, water content and time on main quality components. The results show that:1. On a certain condition,water content keep on a level after a certain time storage. On three humidity treatments in 40℃,it need 24 hours to get banalce,but 50℃and 70℃need 6 hours. According to variation of tea water content on certain condition, we can effective control for tea water during research and produce.2. Inclusion of green tea have change during storage after different treatment. And those change taken place in 5days.3. After be treated 1 to 6 hours,the content of Tea polyphenols has the fluctuation change law on room temperature and different temperature and humidity. Comparied with initial content , Tea polyphenols has increased. Be treated 1,3,6 hours respectively, Tea polyphenols content has a large range after 5 days, the relative variation higher 100% than CK.4. Catechins content has a declined trend during storage after different time treatment. In natural state ,content decrease slowly,more slow40 days later. But content still decrease sharply after be treated.5 . In this treatment ,the variation of amino acid the same as Tea polyphenols. During the whole process, amino acid has the fluctuation change law. The difference be showed after 5 days. Based on variation,low temperature,long time,or high temperature,short time have more influence.6. The variation of coffine is different with high temperarture and high humidity after short time treatment. In 100 days,there is a little change about coffine. Acordding to analysis,the difference from temperature,water and time. The actural reason need further study.7. Acrodding to practial factory produce, we suggest temperature 40℃~50℃, humidity about 80%,water 7%~10%,time 3h~6h.
Keywords/Search Tags:Greentea store Teapolyphenols, liquorchromaticity aminophenol, Coffine, factor
PDF Full Text Request
Related items