Purification And Structural Characteristics Of Non-starch Polysaccharide From White Kidney Bean(Phaseolus Vulgaris L.) And Its Application In Bread

Kidney bean belongs to Phaseolus vulgaris,including red kidney bean,spotted kidney bean,red spotted kidney bean and white kidney bean.It has many physiological activities,such as decreasing blood sugar and blood fat,and cancer prevention.In this study,we selected white kidney bean as raw material for the non-starch polysaccharide preparation(Kidney bean non-starch polysaccharide,KBNSP)and subsequent structural characteristics analysis.At the same time,the influence of DHPM treatment on the basic structural characteristics of KBNSP was studied.In order to enrich its area of application,the kidney bean bread was developed in this study.The main research contents are as follows:1.Basic physical and chemical properties of KBNSP were analyzed.KBNSP was extracted by buffer-enzyme method,and de-proteined by Sevag method.The contents of sugar,uronic acid and protein in KBNSP were 45.63%,17.53%and 7.71%,successively.KBNSP contained eight different kinds of monosaccharides,which were Rha,Ara,Gal,Glc,Xyl,Man,GalA and GlcA.Ara(36.54%)was the highest in the content.The molecular weight distribution of KBNSP was not uniform,and it mainly contained three components with a corresponding molecular weight of 300.67,11 1.30,and 18.16 kDa,successively.The FT-IR spectrum showed KBNSP was a heteropolysaccharide containing ?-type pectin structure.2.Structural characteristics of a pectin component purified from KBNSP were characterized.We obtained four fractions from KBNSP by DEAE-Sepharose column separation.KBNSP-0.3M was homogeneous in molecular weight distribution.The content of sugar and uronic acid was 61.88%and 28.84%,respectively.KBNSP-0.3M was subjected for uronic acid reduction and methylation analysis.Mmain residues in KBNSP-0.3 M included T-Arap,T-Galp,1,3-Galp,1,6-Galp,1,3,6-Galp,T-GalAp,T-Xylp,1,4-Xylp,1,2,4-Xylp,1,4-GalAp,l,3,4-GaIAp and 1,3,4,6-GalAp.It had a high degree of branching.Residues of 1,3,6-Galp and T-Arap were typical arabinogalactan,while 1,4-GalAp,1,3,4-GalAp,1,3,4,6-GalAp,T-Xylp,1,4-Xylp,and 1,2,4-Xylp indicateed the presence of polygalacturonan.These results suggested that KBNSP-0.3M was still a mixture of polysaccharide having different structure.3.Effects of different pressures of DHPM treatment on the structure of KBNSP were explored.The results showed that there were no significant changes in the characteristic absorption peaks in FT-IR spectrum,monosaccharide composition,relative molecular weight,and morphology of KBNSP after DHPM treatment.The above results indicated that DHPM treatment did not affect the primary structure of polysaccharides.4.A preliminary study was conducted on kidney bean bread.Effects of different kidney beanflour additions(5%,10%,and 20%)on the bread sensory evaluation,texture,and aging properties were systematically investigated.aThe optimal addition amount of kidney bean flour was found to be 5%.Compared to fresh dough breads,bread by using of the frozen dough breads was slightly reducing in quality,but still within an acceptable result.In summary,the structure of pectin purified from the non-starch polysaccharide(KBNSP)from kidney bean was initially analyzed.Pectin has a variety of physiological activities,and these properties are closely related to its structure.Understanding the structure of KBNSP-0.3M lays a solid foundation for its future structure-activity relationship study.In addition,the optimum amount of kidney bean in the bread was 5%.Then,a frozen dough added with kidney bean powder was developed for bread making in large scale,while its quality of resulted bread was slightly decreased.The studies enhanced the application value of kidney bean in food industrial production.