Extraction,Purification And Characterization Of Tea Saponin From Aqueous Phase Obtained In The Aqueous Extraction Of Camellia Seed Oil

Tea saponin,also called theasaponin,is a general name of pentacyclic triterpene compound based on oleanane-type.It widely exists in the seeds,flowers,fruit,stem or other part of theaceae plants.Tea saponin has lots of functions.It plays quite good abilities of decreasing the surface tension and foam performance as a nonionic surface active agent.At the same time,tea saponin also has the antibacterial activity,anti-inflammatory activity,antioxygenation,the ability of reducing blood pressure and blood lipid,inhibition alcohol absorption and protecting the stomach and so on.All this make tea saponin very potential both in medical and cosmetic industries.This study focuses on the extraction and utilization of tea saponin from the by-products,which could make a great contribution to the economic development and environmental protection.The sample studied in this paper was the aqueous phase obtained from the extraction camellia seed oil with ethanol,which was abundant in tea saponin.Tea saponin was separated and purified by the technique of ultrafiltration and macroporous resin,and after that the structure of the tea saponin was analyzed and identified by different methods.At last,the changes of properties of tea saponin product after hydrolysis were studied.The main research contents and results are as follows:1,Ultrafiltration technology was used to separate and purify the tea saponin from the aqueous phase.The optimal ultrafiltration condition was obtained through single factor experiment.Result showed that when 10 K ultrafiltration of PLCGC material was used and diluting the aqueous phase to 4 times,and adjusting the aqueous phase pH as 7.0,and adding 3 times water during last ultrafiltration period,the transmittance ratio and purity could reach as high as 64.39% and 84.16%.2,Purification of tea saponin with macroporous resin XR910 X was investigated in this part.It was found that the tea saponin adsorption by XR910 X would be matched by Freundlich Model and the optimal purification conditions were as following: the loading sample was crude tea saponin solution with pH 6.0,and the loading volume 1 BV,loading velocity 1.71 BV/h.Then deionized water and 0.075%(w/v)NaOH solution were used to remove impurity with 1.71 BV/h velocity and 2 BV volume.At last,90% ethanol of 2 BV was used as eluent to desorb the tea saponin with the ethanol flow rate was 1.71 BV/h.Under that condition,the recovery rate of tea saponin was 70.34% and the purity was 94.26%.3,Preparation of liquid chromatography,infrared spectrum,monosaccharide composition analysis of the hydrolysate,and HPLC-MS were used to analyze the structure of the main kinds of saponin monomer compositions identified from last part.Result showed that the main monosaccharides in the sugar chain were glucose,galactose,xylose and arabinose.Seven kinds of saponins were identified and their relative molecular masses were about 1000 ~1511.4,Bioactive properties of tea saponin product after hydrolysis were studied.It was found that tea saponin behaved much better in surface activity than hydrolysis product which was completely lost its sugar structures.The surface tension of water could be decreased from 72.12 mN/m to 32.53 mN/m by tea saponin with the concentration of 2.5 mg/m L.What's more,the ability of removing DPPH and reducing power was increased significantly after hydrolysis.But the tea saponin product and its hydrolysate showed a similar ability of removing ABTS+.In general,the antioxidant capacity of hydrolysis product was better than that of tea saponin.As for the antibacterial ability,tea saponin surpasses hydrolysis product,both of them can inhibit the growth of yeast,followed by bacillus subtilis and escherichia coli,but for aspergillus Niger,they had no antimicrobial resistance.Hemolytic of tea saponin is far higher than that of hydrolysis product.The hemolysis ratio could reach as high as 83.92% under 200?g/mL tea saponin,while the hemolysis ratio of hydrolysis product was only 21.54% at the same concentration.The tea saponin lost its sugars through hydrolysis reaction,so all the results showed that the sugar chain in tea saponin played a very important role on its physiological activity.Once the sugar chain was hydrolyzed or broken,the activity of tea saponin will badly change.