Changes Of Aroma Constituents Of Instant Black Tea During Processing And The Research Of Aroma Retention Measures

In recent years,instant tea has become a kind of popular drink at home and abroad,meanwhile,production and marketing of instant black tea got the most.However,the lack of instant tea aroma has not find a better solution.In order to explore the change rule of aroma in instant tea processing,and find out the key points of aroma loss,this paper track the processing of instant black tea to study the change of aroma in each stage.And then take measures from the key points to seek instant black tea aroma retention methods,provide reference for the research of high aroma instant black tea.By using different two kinds of pretreatment methods--simultaneous distillated extraction method(SDE)and headspace adsorb method(HAS)to extract tea aroma,and combining the technique of gas chromatography-mass spectrometry(GC-MS)to detect aroma composition,it contrasted the effect of different pretreatment method,selected a better detection method.Then track the change of aroma in instant black tea processing to explore the change rule of aroma loss.The positive correlations of aroma characteristics between instant black tea and its processing raw materials are discussed in this article.In addition,it contrasted aroma characteristics of black tea from different regions and different grades to provide suggestions for the selection of instant tea processing raw materials.The influence of extracting time and drying methods on tea aroma were studied,it also analyzed the loss of aroma in decreaming--the commonly used processing step in the production of instant tea.Moreover,instant black tea processing technology optimization suggestions were put forward,too.From this a few aspects,strive for retain the original aroma of tea as possible,and produce high aroma instant black tea,provide technical support for instant black tea market development.The main results were as follows:1.SDE method is better as it can extract more rich aroma components than HAS,relatively,it can comprehensively reflect the features of the aroma of black tea and instant black tea.So it finally selected SDE as the aroma pretreatment way,unified SDE with GC-MS technology as the fragrance detection and analysis method in the follow-up test.2.The aroma of black tea raw materials gradually lost in the process of instant black tea processing,effect of processing technology on instant black tea aroma is obvious.Aroma loss in the extraction and concentration is most serious,the types and content of aroma components in instant black tea are far from that of black tea raw materials.At the same time,loss rate of different types of aroma components is also very different,of whichhydrocarbon compounds loss the most,while ester compounds loss it least relatively.3.The higher the raw black tea aroma is,the higher its instant black tea aroma be.Sri Lanka BOP,Indonesia BOPF and India Assam BOPSM got good aroma characteristics,choose a higher grade black tea as raw materials for the instant black tea processing is more beneficial.In order to retain the original tea aroma as much as possible,in the manufacturing process,extracting time 80 minutes,freeze drying be suggested under the condition of yield meet the requirements,additionally,it is better to not take alkali decreaming processing way.