Tea Processing Technology Research Based On Room Temperature Pressure Dehydration Methods

Room temperature compression dewatering method is an important part of tea processing dehydration method, Compared with common heating drying and freeze drying dehydration method, it has the advantages of low energy consumption, low cost, easy operation, etc. it also has been widely used in other areas of production, at the same time, this method has implemented the basic automation, continuous and scale. How to apply the ambient pressure dehydration method into tea processing, display its application and technological advantages has become an important topic of tea researchers.This paper based on room temperature compression dewatering mechanism of innovation, perspective from the research hotspots in the field of modern tea, exploring its special value in the process of tea processing. For room temperature pressure dehydration methods are used to improve the effect of the summer and fall green tea quality evaluation, studying the effects of summer and autumn green tea quality under different tenderness, seasonal raw materials and different compression degrees of dehydration. Combined with the effect of boiling water blanching on room temperature compression, decompressing sublimation dehydration to prepare low caffeine tea and reducing caffeine to evaluate. Studying the effect of different compression degree of dehydration, process and pretreatment of tea sample decaffeination effects and comprehensively analyzing and evaluating the low caffeine tea quality; evaluating the effect of room temperature pressure dehydration back juice preparing cold tea,researching the effects of the different compression degrees of dehydration, return sauce process to cold tea,and getting the evaluation and dynamic analysis of quality of cold tea. The result showed that:(1) Innovatively apply room temperature compression dewatering way into modern tea processing hot research field. successfully improved the quality of the summer and fall green tea by use room temperature compression dewatering way, prepared the low caffeine tea, its caffeine content is 0.93% and lines with the national standard, at the same time, Prepared soup of cold tea extract that its content is more than 80% compare to the country’s traditional hot tea soup.(2) The research of normal temperature pressure dehydration methods used for tea production technology to improve quality of summer and fall green tea showed that:tea was green color after processing, strong aroma of chestnuts, taste sweet, bright light yellow green soap color, yellow green soft leaves, composite scores higher than the comparison of traditional liquor tea samples, summer tea’s quality has been improved obviously; Normal temperature pressure dehydration improve the quality of summer tea by adjusting the total tea inclusions and its ratio, Among them, the tea quality in pressurized 4ml/100g dehydration processing effect is best, the proportion of phenol ammonia is the lowest (8.36), the water extract amount is proper(34.54+0.08)%. quality improvement effect to summer one bud two leaves of the raw material is obvious, but it is a bit poor effect to autumn tea, dry tea’s color, aroma, taste, tang are not as good as summer tea;(3) Room temperature pressure dehydration methods used in the study of preparation technology of low caffeine tea, combine with decompression distillation means of removing caffeine innovatively, The results show that compared to traditional liquor controls, compressing decompression and sublimation dehydration treatment way for preparing tea after boiling water blanching, tea caffeine removing rate can reach 75.00%, the processed caffeine content was only (0.93+0.03)%, it has reached the domestic indicators of low caffeine tea caffeine content (Acaffeine≤1%); Among them, the effect of after the early rubbing pressure dehydration 4ml/100g, knead compound leaves with solvent 60% edible 4ml/100g knead early (leaf) for sample processing tea caffeine before removal is best; Sample processing tea scent is more abundant, elegant taste is more pure and mild, bitter reduce, and the water extract, retention rate of tea poly phenols, amino acids, and soluble sugar is over 85%; Amino acid composition reduce two categories after processing of tea samples, theanine increases 0.27 mg/g, total amino acid is basic invariable; total catechins lower by 0.94%, including ester type catechins decreased by 0.86%, the ester type catechins decreased by 0.07%, the sensory manifest astringency easer; Detecting that the relative contents over 1.00% of the aroma components in processing tea samples is more than 5 kinds compare to traditional stir fixation. and the relative content of linalool, benzyl alcohol is higher, respectively processing of tea aroma components were 14.69%,11.52%.(4) Normal temperature pressure dehydration method was used to prepare cold tea technology research, using of the "return to juice processing innovatively, collecting tea juice after pressure dehydration processing, evenly spraying it to the surface of the tea, the results showed that:the effect of room temperature pressure dehydration to return juice tea,improve the cold tea soup extract content is obvious; Among them, the after early rubbing pressure dehydration is 6ml/100g, and returning to juice processing effect after wool fire is best; Deal with cold water for brewing tea sample 10 min, its content will more than 80% compare to traditional soup hot tea extract, water extract content could achieved 72%, significantly exceed the traditional liquor cold tea soup, basically meeting the requirements of cold tea; Processing bubble tea kind of cold water quality is better than traditional liquor, and sensory quality water brew liquor approaches to the tradition, the tea polyphenols, amino acids and soluble sugar of dissolution rate in cold tea soup reached more than 70% of the traditional liquor hot tea soup, but caffeine content is extremely low.