| JiangXi is a citrus peel-rich province,the citrus peel hasn’t been used very well and the vast majority of them had been discarded directly.Citrus peel residue is an ideal raw material for industrial production of pectin.Pectin’s commercial production had long been monopolized by Europeans and Americans.However,the home-produced pectin has deep colour,poor gel strength and low quality.In this paper,we choose the citrus peel as the material to extract pectin,optimized the extraction process of pectin,and prepared MCP(Modified Citrus Pectin)from CP(Citrus Pectin),then campared the different physico-chemical properties between CP and MCP.Meanwhile,we designed a pectin project of 300 ton yearly output,hoping to make a theoretical foundation of CP and MCP’s industrial production and application.The main results are summarized as follows:1.We prepared F-CP and D-CP from fresh and dry citrus peel,and campared the extraction yield and quality of these two pectins.The research found that D-CP and F-CP had the yield of extracted pectins were 3.63%and 12.27%.The quality analysis of F-CP and D-CP were 77.29%and 74.98%galacturonic acids,67.5%and 66.7%methoxy groups,179.8 and 153 gel strength.The results of rheological measurements shows that 1%F-CP and D-CP exhibit pseudo-plastic behaviour and the F-CP’s apparent viscosity is higher than the D-CP,this result are consistent with the results of Mw.The results above demonstate that these two raw materials can meet the same requirements of commercial pectin’s production,2.The hot acid extraction process of pectin in citrus peel was studied with the index of yield and pectin quality.Synthesizes the single factor experiment results,the optimum extraction conditions were:60 min at 85 ℃ and pH value is 2.0,the ratio of material to solvent is 1:10(w/v),and the amount of sodium hexametaphosphate is 0.5%(w/v).3.MCP is produced from citrus pectin via pH modification.The physicochemical properties had been characterized and the results showed that:The galacturonic acids content,degree of esterfication and Mw of CP and MCP were 70.55%and 77.12%,68.4%and 10.3%,111.8 kDa and 21.2 kDa.The neutral sugers content of CP and MCP were 14.1%and 12.5%.The monosaccharide composition has little change,mainly contents Rha,Ara and Gal,also contains a small amount of Fuc,Glu,Man.The Ara content decreased and Rha and Gal content basically unchanged.The results of Ultraviolet spectrum scanning showed that CP and MCP contain no impurities such as protein and nucleic acid.The IR scanning results showed that the CP and MCP has characteristic absorption peak of pectin4.Comparison of the rheological properties of CP and MCP.The results of rheology test showed that the rheologieal behavior of CP and MCP was a typical pseudoplastic fluid and MCP solution presents the shear thinned phenomenon under the function of shear rate.Within a certain range,increased temperature and decreased pH will lead to a decline of apparent viscosity in the CP and the MCP solution.We can find that temperature had great influence on the CP solution,while the apparent viscosity of modified citrus pectin is much more dependent on pH than citrus pectin.CaCl2 can cause the apparent viscosity of pectin solution increasing,while little change of the apparent viscosity of pectin solution was happened when added with NaCl.The difference of rheological properties between CP and MCP mainly due to the MCP’s shortening structure and lower degree of esterification.5.Designed a pectin project of 300 ton yearly output.The pectin plant mainly produces citrus pectin and medicinal pectin.The total investment of the project is 21.25 million,including 14.25 million’s fixed assets and 7 million’s current capital.Construction land of this project is 19600 m2 overall floorage is 9514 m2.Upon completion,these projects are expected to achieve annual output capacity of 300 ton of pectin.Annual sales revenue reach 27 million,annual tax 3.79 million yuan,a 42.2%return on investment,and payback period is 2.2 years. |
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