| At present,the instant tea market is still relatively single,mainly based on the raw materials for food industry,.there are few instant tea used for direct drink,.Most of the instant green tea on the market shows the phenomenon of low aroma,far from the flavor quality of the original tea,so the key problems of instant tea production,such as the lack of aroma;the lack of flavor characteristics;and the poor cold solubility,need to be improved.In this study,the fresh leaves from one bud,two leaves to three leaves of Huangshan big leaf species were selected.Based on the traditional processing technology of Huangshan Maofeng,the technology of light shake green,full spectrum light withering and vacuum freeze-drying were introduced to process the special new floral flavor green tea material suitable for instant green tea,and the cool water soluble floral flavor instant green tea was developed from this material.The effects of key processing technologies,such as shaking green,lighting and vacuum freeze-drying,on the flavor substance and aroma of tea,as well as the development and quality analysis of instant tea products were analyzed.The results are as follows:1.The effect of shaking green,lighting and vacuum freeze-drying on the taste substance of tea: a.Both shaking green and lighting are beneficial to reduce the content of tea polyphenols,which have little influence on amino acids,and reduce the phenol-ammonia ratio of tea,thus reducing the bitter taste of tea soup and increasing the freshness of tea soup.b.Shaking green and lighting had great influence on the content of simple catechins in the dried samples,which showed that the content of C increased;the content of EGC and EC decreased;GC was stable,;the total content of simple catechins decreased,;and the content of simple catechins in the freeze-dried samples had little change.The results showed that the content of EGCG,ECG and GCG decreased after shaking green and lighting,but the content of ester catechins decreased after light.2.The effects of shaking green,lighting and vacuum freeze-drying on the aroma of tea: a.shaking green and lighting can increase the kinds and contents of aroma compounds,especially the combination of shaking green and lighting.b.Shaking green and lighting at the same time is conducive to the accumulation of dried like flower fragrance,but the effect of single effect on the increase of flower fragrance is not obvious;vacuum freeze-drying is conducive to the retention of fragrance substance content of flowers,but at the same time,it will also retain green grass air.3.The best times of shaking green tea and lighting time: in this experiment,the aroma of shaking green tea twice for 120 min is the best.Under this condition,the dried tea has rich fragrance and mellow taste.4.The best extraction technology of cold-soluble flower flavor instant green tea:response surface analysis showed that under the conditions of extraction temperature 40 ℃,extraction time 20 minutes and tea water ratio 1:20,the fuzzy mathematics score of tea soup was the highest,86.55,and the extraction rate could reach 26.79%.5.Quality analysis of instant green tea made from different raw materials of tea: the fresh and mellow taste of the instant green tea made from the new Huaxiang green tea has obvious flower fragrance;the traditional Maofeng green tea has no flower fragrance,with the main aroma of chestnut,with the fresh taste,but not mellow enough.(8)Aroma analysis of instant green tea made from different tea materials: there are many kinds of aroma substances in the instant green tea made from new-type flower scented green tea,and there are high content of linalool,geraniol,Neroli tertiary alcohol and other flower scented aroma substances.However,the flower aroma of instant green tea with traditional Maofeng green tea as raw material is less and less. |
