| Cyperus esculentus L also called Tigernuts,are native to Africa,perennial herb and wide adaptability,it has been planted in more than 20 provinces and regions in China,planting scale and production increase year by year.Oil,starch,sugar,protein,cellulose and other nutrients are rich in Cyperus esculentus L,the content of oil is20%~36%.Oleic acid and oleic acid are the most important components in oil of Cyperus esculentus L,which can improve human immunity and prevent cardiovascular diseases.It has great market value.The traditional pressing method would destroy other nutrients in Cyperus esculentus L,reducing the value of comprehensive utilization;the solvent extraction of oil will cause the residual solvent,but also pollute the environment.In this experiment,use the Cyperus esculentus L as raw material,first pretreating,and then the extraction of Cyperus esculentus oil with traditional aqueous enzymatic method,centrifuge,demulsification,refining.Finally,the enzymolysis centrif-uge liquid was treated with two-oder-membrane technology to recover the polysaccharide of Cyperus esculentus L,pollution was controlled in the process and curbed from the source,reduce the production of waste liquid and realize clean productionaegorded with the recycle economy tenet.During the pretreatment of Cyperus esculentus L,the biggest innovation of this experiment was use an improved aqueous enzymatic method to extract Cyperus esculentus oil,namely acid treatment of Cyperus esculentus L.The main purpose is to use simple and effective way to break the plant cell wall and release the oil,increase the oil extraction and do not destroy the effective components.The main conclusions are as follows:(1)The optimul conditions for the extraction of acid was explored by a series of single factors and orthogonal experiments.The results showed that the optimum conditions were:the ratio of material to liquid was 1:11,acid extraction pH was 4,acid extraction temperature was 50?,and acid extraction time was 5h.The order of the influence of each factor is the acid extraction pH>temperature>time>feed ratio.(2)Compare with the effects of 5 enzymes,pectinase,acid protease,alkaline prote-se,alpha amylase and cellulase,on the extraction rate of oil from the Cyperus esculent-us L.The results showed that alkaline protease is the best.(3)The optimul conditions for the extraction of Cyperus esculentus oil with aqueous enzymatic method was explored by a series of single factors and orthogonal experiments.The results showed that the optimum conditions were as follows:the enzyme time was 4h,the enzyme pH was 10,the enzyme dosage was 2.5%,and the enzyme temperature was 55?.The order of the influence of each factor was the enzyme time>the enzyme pH>enzyme dosage>the enzyme temperature.The oil extraction rate is 86.27%.(4)The condition of demulsification:adding water soluble salt in the emulsificatio-n layer and stirring 2.0h at 60?,the oil of Cyperus esculentus L was obtained by centrifugation.Refiningprocess:hydrateddegumming,alkalirefiningand deacidification,activated carbon decolorization,cooling crystallization dewaxing.(5)Recovered the effective components from the waste solution.The membrane and its working parameters of the two-oder-membrane technology were determined through experiments.The best membrane was combined with ultrafiltration membrane I and nanofiltration membrane II.The ultrafiltration membrane I inlet pressure is0.24MPa,the outlet pressure is 0.16MPa,the surface velocity is 4.0m/s,the temperature is 35?,concentration multiplier is 17.42 times,the average flux is 92.78L/(h·m~2).The transmissivity of Cyperus esculentus polysaccharide was 97%,the removal rate of solid substance was 26.85%,and the removal rate of protein was 89.32%.Nanofiltration membrane II inlet pressure is 1.50MPa,the outlet pressure is 1.20MPa,the surface velocity is 4.0m/s,the temperature is 40?,concentration multiplie is 10.20 times,the average flux is 41.07L/(h·m~2),Cyperus esculentus polysaccharide retention rate was100%.After two-oder-membrane technology,the protein removarate was 89.32%,and the recovery rate of Cyperus esculentus polysaccharide was 97.82%.(6)The economic benefits of aqueous enzymatic method,pressing method,solvent extraction were compared.Finally,it shows that the annual profit after tax is 9 million700 thousand yuan.The project is feasible. |
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