Ultrasound Assisted Water Extraction,Puriifcation And Antimicrobial Activity Of Teasaponin From Camellia Cake

There are abundant of camellia cakes in China which contain teasaponin about10%～15%. From the studies in recent years, it is shown that teasaponin not only has a goodsurface activity, but also has a variety of biological activities such as anti-inflammatory,antioxidant, antibacterial, antihypertension, fish toxicity, hemolytic effects,alcohol-absorbing inhibition and gastrointestinal protection. Since teasaponin has beenwidely used in medicine, daily chemicals, pesticides, building materials, food and otherareas, making full use of the camellia cake resources is of great significance. In this thesis,using the camellia cake as the raw material, the process of extraction andflocculation-purification of teasaponin are investigated, and the antibacterial activities ofteasaponin products are also studied.The main contributions in this thesis are as follows:(1) The extraction process of teasaponin. Teasaponins are extracted from defattedcamellia cake by ultrasound assisted water. During this process, the effect of liquid to solidratio, ultrasound power, extraction temperature, pH value and extraction time on theextraction are also investigated. Lastly, the optimum extraction process conditions areobtained by the orthogonal experiment of L9(34), in which the extraction rate of teasaponinis higher than10.06%. The optimum conditions are listed in detail as follows: extractiontemperature is60℃, ultrasound power is600W, pH value is12and liquid to solid ratio is10:1(ml:g).(2) The purification process of teasaponin by using chitosan flocculation. Firstly, thestate of teasaponin in the solution and flocculation impurity are analyzed theoretically.After that, the critical micelle concentration(cmc) of crude teasaponin is determined byWilhelmy platinum plate method. Lastly, the effect of the chitosan quantity, teasaponinconcentration and placing time on the flocculation-purification are investigated. Theexperiment result shows that the cmc of crude teasaponin is0.25%and the optimumflocculation process conditions are shown as follows: chitosan quantity is2.5ml/g,teasaponin concentration is1.2%and placing time is3h. Moreover, the experiment resultsdemonstrate that the effects of teasaponin concentration on the flocculation purification isrelated to the process of the shape of the teasaponin micelles formed in aqueoussolution.(3) The antibacterial properties of teasaponin products. Inhibition activity and Minimum Inhibitory Concentration (MIC) of E.coli, Stapylococcus aureus andPseudomonas aeruginosa on pure teasaponin, teasaponin product(TS1) which made byultrasonic water extraction-flocculation purification-drying process and ethylene-1,2-pairs(dodecyl ammonium bromide)—C12-2-12.2Br-1are investigated. The results show thatpure teasaponin, TS1and C12-2-12.2Br-1have antibacterial activity to all tested bacteria. Forpure teasaponinn, the corresponding MIC of all the tested bacteria are as follows: E.coli is3.2mg/ml, Stapylococcus aureus is12.8mg/ml and Pseudomonas aeruginosa is25.6mg/ml. For TS1,the resulting MIC of all tested bacteria are listed as follows: E.coli is12.8mg/ml, Stapylococcus aureus is51.2mg/ml and Pseudomonas aeruginosa is51.2mg/ml.For C12-2-12.2Br-1n, the corresponding MIC of all tested bacteria on as follows: E.coli is3.12ug/ml, Stapylococcus aureus is1.56ug/ml and Pseudomonas aeruginosa is100ug/ml.(4) The antibacterial effects of TS1combined with C12-2-12.2Br-1to against all testedbacteria are investigated. The results demonstrate that the impurities in TS1inhibit theantibacterial activity of C12-2-12.2Br-1. Therefore, it is inappropriate to use TS1combinedwith C12-2-12.2Br-1to resist all tested bacteria.(5) Preparation process of teasaponin antimicrobial products. Minimum InhibitoryConcentration (MIC) of all tested bacteria on four kinds of teasaponin liquid productswhich prepared by ultrasonic water extraction-flocculation purification-evaporationconcentration process were investigated. Compared with the antibacterial properties of TS1,the results show that the antibacterial properties of the liquid products of teasaponin is notbetter than that of TS1. Therefore, it is concluded that ultrasonic waterextraction-flocculation purification-drying process can be used for the preparation ofteasaponin antimicrobial products.