Study On The Extraction And Separation Of Rutin And Polysaccharides From Tobacco Waste

Tobacco is one of economically important specialty crops,it is also a traditional Chinese medicine with long history.There are numerous chemical compounds in tobacco,and many of them are valuable with biological activities.In this study,major tobacco active compounds and research progress reported in the literature worldwide are reviewed and discussed.The extraction and separation technology of less-studied active components such as rutin and polysaccrides in tobacco waste were studied and established.This study could be as reference for extending the approachs of tobacco effective use,developing active compounds with the potential value and improving the comprehensive utilization of tobacco waste.The main research results are summarized as follows.1.The ultrasound-assisted extraction（UAE）conditions of rutin in waste tobacco leaves and the parameters of enrichment rutin by macroporous resin were optimized.Based on single factor experiments,the optimum extraction technics was obtained through the analysis of response surface method（RSM）which was designed by Box-Behnken Design（BBD）.The optimal parameter values were as follows:liquid-material ratio 30 mL·g^-1,ethanol concentration 33%,ultrasonic time 20 min at57℃,total extraction 3 times.Static absorption and desorption experiments were performed to contrast the isolation ability of 3 types of macroporous resin.Results indicated that D101 resin possessed the better absorption and desorption capacity.The optimum technic parameters of isolation rutin from crude extract of tobacco waste were investigated and confirmed.The major parameters were:the concentration of feeding solution was 2 mg·mL^-1,flow rate 2 mL·min^-1,the average adsorption was3.18 mL·cm^-3,eluent was 70%ethanol,eluent flow rate was 2 mL·min^-1,and the average dosage of desorption was 1.28 mL·cm^-3.The rutin obtained by the optimal extraction and enrichment technics was determined by using high performance liquid chromatographic（HPLC）method.The results show that rutin content in waste tobacco leaves was 4.9 mg·g^-1.The rutin content in the crude extract obtained by the optimal UAE technique was 11.81 mg·g^-1,recovery rate was 95%.By means of macroporous resin enrichment,the rutin content was 85.03 mg·g^-1 with 86.8%of recovery rate,and product purity increased by 7.2 times.2.The ultrasonic-assisted water extraction conditions of water-soluble polysaccharides from discarded tobacco were optimized;water-soluble polysaccharides and alcohol-soluble sugars were extracted,their antioxidant activities were measured in vitro.In this experiment,the recovery yield of polysaccharides as the evaluation criteria,based on single factor test,technique parameters were investigated by using analysis of RSM designed by BBD.The results showed that the optimum extraction parameters were extraction temperature 69℃,ultrasonic time 20min,liquid-material ratio 109 mL·g^-1.The recovery yield of polysaccharide was92.36 mg·g^-1 with the optimum condition.In comparison of three methods for removing the protein in water-soluble crude polysaccharides and found that TCA method was suitable.By separation and purification from water-soluble crude polysaccharides,the polysaccharide fraction,named TP-1,was obtained.The molecular weight of this polysaccharide is no less than 14 kDa.Two polysaccharides,named TP-2 and TP-3,were purified from the alcohol-soluble sugar crude extract.The results of antioxidant experiments show that TP-1 with activities of significant scavenging hydroxyl free radical and ABTS free radical,and IC₅₀（50%inhibitory rate）were 3.68 mg·mL^-1 and 19.30 mg·ml^-1,respectively.TP-2 had weak antioxidant activity compared with TP-1,and TP-3 did not have antioxidant activity.3.Through summarizing the national and international related patents and research reports as well as the experimental results of this study,considering the solubility characteristics of substances and the like-dissolves-like rule,a preliminary extraction and separation technology combined tranditional and novel techniques such as UAE was designed for co-producing a variety of active components from tobacco waste.Because this joint production technology has potential to produce numerous of tobacco active compounds（such as chlorogenic acid,rutin,scopoletin,solanesol,nicotine,active polysaccharide and tobacco protein）step by step,therefore it could allow us to maximize utilization of tobacco waste.