Characteristics Research On Chemical Composition And Phloem Fiber Of Annual Kudzu Stem

At present,with the development of cultivated Kudzu,a large number of Kudzu stem resources of every year need to be further studied and exploited.For the effective utilization of Kudzu stem resources in Hunan and its surrounding areas,this study systematically studied the preparation technology of Kudzu based on the analysis and study of its basic nutrient components by using alkali treatment technology,high temperature alkali boiling-ultrasonic treatment technology,breaking high temperature alkali boiling-ultrasonic treatment technology,affecting the best technological parameters of degumming and refining Kudzu.The analysis method of single fiber characteristics and the optimum technological parametersaffectingthedegummingandrefiningofKudzuwereobtainedasfollows:The results of physicochemical characteristics analysis of seven Kudzu stem samples showed that the indexes of PO(Pueraria lobata(Wild)Ohwi)stem and PB(P.thomsonii Benth)stem had littledifference on the whole,but there were obvious differences among harvesting time,region and varieties;the basic nutrient components of PO stem decreased with the increase of growth time,but the insoluble fibers increased obviously;At the same sampling time,the crude fat,crude protein and total fiber content of PB are hinger than PO,But the total sugar content and ash content are lower than PO;The KS7 is superior to ordinary PO.If Kudzu stem as the raw material for Kudzu fiber,suggest for the Kudzu stem with longer growthperiodbeselectedasrawmaterial,buttheinfluenceofregionshouldnotbeignored.The results of preparation technology of Kudzu showed that alkali treatment had the advantages of shorter time,lower residual gum rate and higher breaking strength.The physical and chemical properties of seven Kudzu samples obtained by alkali treatment showed that the PO were generally higher than those of PB,and the breaking strength of PO showed obvious differences among regions and varieties.The cellulose content of PB is obviously different among regions,and the hemicellulose content of PB is obviously different among regions and varieties.In general,the hemicellulose content of PB is higher than thatofPO.The research results of single fiber characteristics of Kudzu show that the Kudzu fiber is pretreated by breaking high temperature alkali boiling-ultrasonic method,and then characterized by microscopic photography measurement method.The high temperature alkali boiling-ultrasonic method can make the Kudzu single fiber break and dispersesufficiently,and take clear pictures under the microscope,which lays a foundation for the characterization of single fiber characteristics of Kudzu.The diameter range of single fiber of Kudzu is about 3 ?m~12 ?m,most of them are below 10 ?m,the average diameter is 6.3?m~7.2 ?m,the number of metric branches is 3098.2 m/g~3866.7 m/g,and the linear density of single fiberis2.6dtex~3.2dtex.Thereareobviousdifferencesamongvarietiesandregions.TheresultsofdegummingprocessofcrudeKudzushowedthatalkalitreatmenttemperaturehadthe greatest effect on the residual gum rate of crude Kudzu,and the ratio of material to liquid and treatment time had the least effect on the residual gum rate of crude Kudzu.The power of ultrasonic wave was 500 W,the frequency of ultrasonic wave was 40 kHz,the temperature of treatment was 80 ?,the treatment time of ultrasonic wave was 1.5 h,and the ratio of material to liquid was 1:10.The residual gum rate of crude Kudzu was the lowest(1.15%)and was crude Kudzu residue.By SEM and FTIR observing the surface morphology of Kudzu,the high quality Kudzu products can be obtained after processing the crudeKudzuwiththistechnologicalparameter.This study reveals the physical and chemical characteristics of Kudzu stem in Hunan and its surrounding areas,and preliminarily establishes the preparation technology,degumming technology of Kudzu and the method of analyzing the single fiber characteristics of Kudzu.It provides a solid theoretical and technical support for the efficient utilization of Kudzu stem and has a profound significance for the deepindustrializationdevelopmentof KudzustemandKudzufiber.