Study On Processing Technology And Quality Formation Of The Guanyin Tea

Sichuan is one of the acient areas where people processed tea.The spring tea produced there with a high quality which is "high the aroma, strong the taste, enduringly the dunk", so the demand of it deceeds the supply.But due to the strong sun-light and high tempreture, the tea leaves grow fast and with a low tenderaton, which made the tea became bitter and low aroma.So many factorys seldomly producting tea in summer and autumn. And it made a huge waste of the tea resource. Based on the comsuptive character of scented tea, so how to make the best of the tea leaves in summer and autumn, to innovate the processing technology and develop a novel tea to raise the economic benefit of Sichuan tea industry are the most urgent actual production questions. However, the developing of a novel tea named Guanyin tea with the use of mature tea leaves is one of the approaches to solve these promblems.Therefore, the research used the mature materials of summer and autumn tea in Sichuan as materials, studied the processing technology and the quality formation of the Guanyin tea. The results were obtained as follows:1. Developed a tea product named Guanyin tea which was processed with the raw materials of summer and autumn tea in Sichuan. Its sensory evaluation were:tight and silvery green the dry tea, green the soup, fresh and floral the aroma, fresh, cool and mellow the taste, whole and fresh green the leaves. And its general quality was higher than traditional green tea.2. Based on the single factor experiments, the orthogonal test of the key processes were carried out. The processing technology of Guanyin tea was that:a bud with 2～3 leaves of raw materialsâ†'whithering (10min)â†'spreading 1～2hâ†'first flip 2minâ†'spreading 1.5～2hâ†'second flip 3minâ†'spreading 1.5～2hâ†'third flip 5minâ†'reading 2～3hâ†'steamingâ†'twisting (do shape)â†'drying (100℃)â†'products.3. The change of the components contained in the leaves during processing is that: due to the season and picking standard, the overall content of all components contained in Guanyin tea was high. The content of tea polyphenols was been a decreasing trend, which at last decreased 4.73%. The content of tea amino acids was decreased after increasing, and reached the highest point 4.67% due to the laying and preprocessing processes. The contents of caffeine and catechins changed insignificantly,decresed 0.04% and 9.88% separately. The soluble sugar content decreased 0.63% because of the hydrolyzation and reaction for tea aroma formation. Water extracts tended to decrease, with an increase of 5.73%. In the detectation of the Guanyin tea components, the total content of amino acids is about 3.83%, in which a special amino acid theanine was highest, up to 1.7%. Alkaloid content of about 2.80%; total catechins of approximately 23.11%, including simple catechins content of about 16.67%, ester catechins content of about 6.36%, the latter is less than the former about 10%.33 kinds of the aroma compounds of the Guanyin tea have been detected. Several compounds with high content proportion in proper order were: neophytadiene, nerolidol B,β-farnesene, octadecanal, pentadecanal, L-linalool, these six compounds content accounted for 71.39%of the total.4. Selected six tea culvarieties as materials, including Mengshan 11, Meizhan, Mingshan-baihao, Fuxuan 9, Fuding-dabaicha, Chuancha-qunti for processing Guanyin tea, and the sensory evaluation scores from high to low were:Fuxuan 9> Meizhan and Mingshan-baihao> Mengshan 11> Chuancha-qunti> Fuding-dabaicha, in terms of the physical and chemical testing results, Fuxuan 9, Meizhan, Mingshan-baihao, Mengshan 11 have demonstrated superiority in the biochemical composition, which was accordance with the sensory evaluation, it means that they wre suitable for making Guanyin tea especially Fuxuan 9. And the compare of the Guanyin tea processed respectively in spring, summer and autumn showed that the quality of Guanyin tea is best in spring.5. The preliminary selection on mechanical equipment of the Guanyin tea were: 6CST-40 cylinder type water-removing machince,6CR-40 tea twisting machine,6WQ-24 tea-ball speed packeting machine,6CWZ-80 tea-ball shaping machine,6CWM-80 tea-ball loosing and screening multifunction machine,6CH-3 roboticized chain board dryer, 6CHX-70 aroma raising machine.