Study On Extraction And Propertities Of Pectin From Passiflora Edulis Rind

Passiflora edulis rind was used as the raw material and pectin as the r esearch object in the paper.The optimum extraction conditions were optimized by o rthogonal design and response surface test.We syudied the extraction process of pec tin from passion fruit peel And compared the extraction rate of different extraction methods such as acid extraction,compound enzyme extraction and ultrasonic assisted complex enzyme extraction.The pectin was purified by papain hydrolysis.The effe cts of different extraction methods and drying methods on pectin were compared by research on their physical and chemical properties and processing properties.Pectin was modified and the morphological changes of pectin were analyzed.The function al properties and processing characteristics of passiflora edulis rind pectin were verif ied by the application of colonic localization release and gelatinous candy processing.Specific conclusions are as fo llows:?1?extraction process studies show that?1?Study on acid extraction of PectinThe optimum acid extraction conditions were as follows:the pH is 2,the temp erature was 90?,leaching time 2 h,liquid to material ratio of 4:1,under the con dition,the pectin extraction rate is 2.45%.?2?Study on Enzymatic Extraction of PectinThe extraction ability constraction of single enzym were as follows:lignin-ase?extraction rate 2.27%?>Cellulase?1.83%?>Amylase?1.8%?>hemicellulas-e?1.63%?;The composition of the complex enzyme system was as follows:c-ellulase,he micellulase and ligninase;The optimum conditions for the synthesis of pectin by co mplex enzyme were as follows:pH 6,extraction temperature 40?,extraction time3.5 h,liquid to material ratio 6:1,pectin yield 2.61%.The best additions of the compound enzyme components were exp lored by Box-Behnken Design design.The optimum method was obtained by regression an-alysis.The method was as follows:cellulase 0.8%,hemicellulase 1.2%,lignin-se addition is 0.2%.under the optimum e xtraction conditions,the pectin extract-ion rate is 2.63%.?3?Three-level orthogonal optimization experiment designed with ultrasonic time,ultrasonic power and ultrasonic temperature.The optimum conditions of ultrasonic assisted enzymatic method were as follows:cellulase ultra 0.8%,hemicellulase 1.2%,Lignin enzymes 0.2%of enzyme,liquid ratio of 6:1,extraction medium p H4,in250W ultrasonic power wave assisted,water bath 45?ultrasound 45min),the extr action rate is 2.83%.?4?rearch on enzymatic elimination process of proteinThe optimum technological parameters used for the purification were as follows:pH8,the dosage of papain was 0.6%of the peel weight,under the temperature o f 60?for 1.5h.the protein residue is 7.22?g/mL,protein elimination rate is mor e than 90%,the pectin purity meets the national quality standard requirments.compare three methods by extraction rate shows that their extraction ability are:ultrasonic assisted enzymatic method extraction>enzymatic extraction>acid extra ction.And the difference on extraction rate of the three methods was significant,an d the ultrasonic assisted enzymatic extraction could shorten the extraction time effici ently.?2?Effects of different preparation methods on the properties of pe ctin showed that:?1?Different methods of extracted and dried pectin,differs from basic physi cal and chemical properties,though,their indicators have reached the national standar d;extraction methods and drying methods will affect the color of passion fruit pecti n powder;the color of pectin extracted by Acid,enzymatic,ultrasonic enzymatic ext raction changes from deep to light in order;color of vacuum freeze-dried pectin is lighter than hot air dried pectin;extraction method will lead difference in pectin est erification degree and methoxy degree and other basic physical and chemical properti es,pectin from acid extraction has a higher physical and chemical indicators such a s esterification degree\methoxy and amide degree than the enzymatic pectin,and ul trasonic auxiliary effect has no significant impact on basic physical and chemical pr operties of pectin.?2?different extraction methods affect the physical and chemical properties of pectin.Acid extraction of pectin has high gel strength and low viscosity.Enzymati c and ultrasonic methods have better water solubility and emulsification than acid e xtracted pectin.Vacuum freeze-dried pectin is more easily hydrated and swollen to f orm a more homogeneous and stable solution,which is higher in viscosit y than hot air dried pectin,and has better water solubility and emulsifying properties than hot air dried pectin.It's better to choose vacuum freeze-drying as the drying method.As passion fruit pectin is different from the commercial apple pectin,its visc osity is far lower than apple pectin under the same conditions,but with excellent em ulsification activity,and it's emulsification stability is slightly lower than the apple pectin.?3?Molecular structure analysis of passion fruit pectinThe average molecular mass of passion fruit pectin is about 3×10⁶⁵×10⁶Da,which is one order of magnitude higher than that of commercial apple pecti n and classed as the super molecular weight pectin.The composition of the monosa ccharide is:arabinose,galactose,glucose,ribose,mannose,and the composition ratio of monosaccharide is 0.54?arabinose?:0.24?galactose?:0.48?glucose?:0.04?ribose?:0.17?mannose?.Compared with the commonly used apple pectin,it has less side chains.?4?The preliminary study of modified passion fruit pectin propertiesThe degree of esterification of pectin decreased from 12.25%to 2.9%,and the esterification degree decreased from 71.35%to 47.98%.The gel strength decreased f rom 139.9719 g/cm2 to 47.8938 g/cm2,The average molecular mass decreased from 4.56×10⁶ Da to 2.8×10⁶Da.In the FT-IR analysis,the modified passion f ruit pectin still had the characteristic absorption peak of D-Glu galacturonic acid,an d the content of methoxy group The content of carboxyl groups and the content of free carboxyl groups were changed.The morphology of the powder particles change d significantly,the powder particles were obviously smaller,smoother,edge passivate d,besides,the non-crystalline state changed into the crystallization zone and non-cry stalline zone coexistence state after modification,and the crystallization peak type re zembles apple pectin.