Research On Starch Extraction Of The Kidney Bean、Physico-chemical Properties And Application

This experiment with kidney bean as raw materials，the optimum extraction process of kidney bean starchwas studied.then physico-chemical properties of kidney bean starch were studied.basing on the specialcharacteristics of kidney bean starch,one kind of fresh and delicious fine dried noodles was developed.In this experiment grinding and acidic steeping liquor were used as the methods of kidney bean starchextraction, It showed that the yield of the grinding extraction is lower than the acidic steeping liquor, by themethod of single-factor combined with orthogonal test, the optimum extraction condition was reached at thecondition of1:5solid-liquid ratio,8pH,35℃temperature,16h for soaking.The granules, viscosity, crystal type,pasting properties were researched by using Scanning ElectronMicroscope,Brabende brookfield viscometer, X-ray diffraction analyzer，differential scanning calorimeter,laser particle size analyzer.The starch solubility dilatation of kidney bean,potato and maize were compared inthis study.There is the higher amylose content in the starch of kidney bean, the content was39.10%; the crystal typeof the Kidney bean starch belongs to the A-type; granules size of kidney bean starch ranges from10μm to50μm, the average size is26.79μm; the pasting temperature is at74.2℃, peak viscosity is949BU, peakviscosity is much higher; The solubility and dilatation degree is between corn and potato starch. the lighttransmittance of kidney bean starch paste is10.2%, the light transmittance is not good, freeze-thaw stability ispoor, after eight days drainage rate is at58.2%. By scanning electron microscope, most of the starch granulesare ovoid, part for circular and polygons and have smooth surface and no crack.With high quality flour and kidney bean starch as the main raw material,a new kind of composite fine driednoodles were developed, five main factors were studied by the method of single-factor combined withorthogonal test.The optimum condition made the delicious and smooth fine dried noodles of the best qualityare obtained as follow: the ratio of starch and flour3:7,salt1.5%,water40%,sodium alga acid0.8%,egg4%.