The Comprehensive Utilization Of Tea Flower-Extraction And Analysis Of Polysaccharide And Aroma Components In Tea Flower

Tea flowers contain many nutrients and are rich in bioactive substances underlining their great potential and development prospects in the functional food industry. China is a major tea producing country with an annual dried tea flower production of 25.35～50.7 million tons. The use of tea flowers has been proposed to improve the quality of spring tea. This thesis focuses mainly on tea flower polysacchaides (TFPS) and tea flower fragance ,investigating the extraction,separation and purification of TFPS ,extraction of essential oil and making of essences .The best conditions to remove saponin were to use 10 times volume of 60% ethanol according to single factor experiment.To get TFPS: water was used as the extraction solvent, ethanol for precipitation, and vacuum oven for drying. Using single-factor orthogonal trial,we confirmed that the best extraction conditions of TFPS were:temperature 90℃for 1.3 hours,liquid-solid-ratio of 10:1.Tea flower polysaccharide was purified as follows: the proteins were removed first by the Sevage method,then the polysaccharide was bleached and separated by DEAE cellulose,and classified using Sephacryl S-300. By DEAE premilinary separation,we obtained TFPS1 with a purity of 87% and another TFPS2,which was then classified by Sephacryl S-300 to get T1.Analysis of High-performance Gel-filter chromatography showed that the molecular weight of T1 was 79,615 and its purity was high. Preliminary analysis showed that T1 was a kind of water-soluble white mesh polysaccharide, indissoluble in Warm water,without starch, phenolic material, protein, reducing sugar,nucleic acid and peptide in it.It was composed as follows:Mannose:ribose:rhamnose:galacturonic acid:glucose:galactose:Arab sugar = 2.09:0.70:8.56:2.65:10.07:39.94:35.98.Study of fragrance of the tea flower included the effect of heating on the components of tea flower essential oil, optimization of the petroleum extraction conditions and, exploration to CD-embeding. Single factor analysis of petroleum extraction of essential oil showed that : the higher the liquid:solid ratio,the higher the yield of essential oil; extraction was highest in one hour; Extraction yield was directly proportional to extraction times.We recommend the use of extraction apparatus which is devised by cable-extraction principle, shorten the extraction time and increase the times of extraction to increase productivity.But in experiment,the best conditions were to extract the tea flowers with 15 times of petrol ether for 3 times with 1 hour per time.The results showed that: tea flower dried at room temperature was rich in esters with higher aroma; tea flowers dried by 120℃hot steam was rich in alcohol content; tea flower dried at 100℃in an air oven contained the most alkanes, and was not fit to make essence.