Study On Isolation And Charaterization Of Oat Starch

In this study, oat flour was used to study extraction process and physicochemicalproperties of oat starch. The main results are shown as follows.(1) Isolation processes of the alkali and ultrasound-assisted enzymatic of oat starch werestudied in this paper. The process conditions of alkali method were as follows: pH value of10.0, liquid ratio (m/V)1:6, stirring time of90min. Under these conditions, the extractionefficiency of oat starch was85.62%.Ultrasound-assisted enzymatic method of oat starch wasobtained as follows: enzyme dosage1.0%, reaction temperature40℃, hydrolysis time1h,ultrasonic treatment20min, digestion pH value of7.0. Under these conditions, the extractionefficiency of oat starch was88.91%. The results showed that ultrasound-assisted enzymaticmethod is better than the alkali method. Extraction time of ultrasound-assisted enzymatic wasshorter and extraction rate was higher.(2) Physicochemical properties of oat starches from alkali method,enzymatic method andultrasound-assisted enzymatic method were compared.The results showed that: crudefat,amylose and damaged starch contents of oat starch from alkali method were the highestamong three isolation methods; Starch granule morphology can be observed by ScanningElectron Microscope (SEM) directly, results indicated oat starch grains were more complete;Oat starch prepared by alkali method has the worst transparency, retrogradation, freeze-thawstability and thermal stability, the highest solubility and the lowest swelling power and is mostlikely to aging. Oat starch prepared by alkali method has most powerful liquefaction.(3)The commonly used starches (wheat starch, corn starch and potato starch) were usedas compare objects to study the properties of oat starch. The results showed that the contentsof crude fat, amylose and demaged starch of oat starch were the highest among four kindsstarches; Granule of oat starch was small with oval and water caltrop shaped;Polarzation crossof oat starch granules is not very obvious;D10,D50,D90and Dav of oat starch were thesmallest among four starches;The results indicated that oat starch has poorer lighttransmittance, retrogradation and freezing-thawing stability than that of wheat starch, cornstarch and potato starch. Oat starch has the highest solubility and lowest swelling power offour starches. Pasting property of oat starch was closer to wheat starch. Liquefaction degree ofoat starch was larger than wheat starch, corn starch and potato starch.(4)Defatted process of oat flour and the properties of defatted oat starch were studied.The defatted conditions of oat flour were as follows: liquid ratio (m/V)1:4, defatted time of 4h.The contents of crude starch, crude protein and ash were increased and amylase anddemaged starch were decreased after defatted; Granule of oat starch became moreuniform,polarized cross became more obvious and the size distribution changes little afterdefatted; Defatted oat starch had better transparency, retrogradation and freeze-thaw stability;Solubility of oat starch was lower and swelling power was higher after defatted; Peakviscosity of defatted oat starch is elevated and viscosity,final viscosity,retrogradation, andgelatinization temperature were decreased; Liquefaction degree of oat starch was higher thanthat of defatted oat starch.