The Research On Processing Technology Of High Fragrant Dark Black Tea

With more and more further researches on dark tea which identify its multiple-health-efficacy,more and more consumers began to get to the dark tea and the consumption volume of dark tea increases consistently.Though there were many researches and reports relating to dark tea process,researches on fresh raw dark tea fragrance were rare.This thesis,with leaves?a bud three or four leaves?of dark tea as raw materials,and orthogonal test,sensory evaluation,physical and chemical testing and analysis,and volatile fragrance substance testing and analysis as research methods,finds out the best technique combination from diversified process techniques,and promotes the best parameter combinations of new technology of dark black tea with abundant flower fragrance,orange and bright liquor color,thick and profound taste,and sweet aftertaste.Meanwhile,the thesis also conducts repeating and testing experiments.The research results are as follows:1,With fresh leaves of Yusun as raw materials,it could be found through comparing the quality characteristics of new technology of dark tea processed by traditional technique and new technology of dark tea processed by new technique that the new technique could promote both the fragrance and taste.The evaluation score of raw dark tea processed by new technique was 4 points higher than traditional technique,and its aqueous extract was 3.87%higher,amino acid was 0.44%higher,while its phenol-ammonia was lower.Thus,its overall quality was much better.2,With fresh leaves of Bixiangzao and Tiexiang as raw material,orthogonal test was designed of three factors,namely number of rocking processes,fermentation degree,and drying temperature,based on former experiments.Upon results analysis,it could be identified that the best technique combination was A₃B₁C₃?namely 3 times rocking processes,light fermentation,and 120?drying temperature?.And the results showed that the tea processed by new technique has thicker and more profound fragrance,more orange and brighter liquor color,mellower taste and sweet aftertaste.Meanwhile,the rocking process of new technique could effectively decreases polyphenols contents and bitterness and increases amino acid contents so as to harmonize the taste.The dying temperature influences the fragrance of made tea that the fragrance would be low and deep for low dying temperature,and the made team would be carbonized and its fragrance would have scorched flavor for high dying temperature.The raw dark tea processed by the best technique combination has significantly increased kinds of fragrance substances and total contents,especially esters and alcohol.The increase scales of total fragrance substances contents of Bixiangzao and Tiexiang are 21.26%and16.62%.3,The new technique of dark tea is repeatable.Fresh leaves of Bixiangzao and Tiexiang were picked to be processed by same technique.The results show that the highest scores of sensory evaluation are gained by the tea processed by the same technique,namely the best technique combination-A₃B₁C₃?3 times rocking processes,light fermentation,and 120?drying temperature?.And it can be found through volatile fragrance substances testing that the fragrances kinds and contents of both teas are increased.The repeated experiments have the same results that the quality is improved.