Physicalchemical Properties Of Oat Starch And Oat Resistant Starch Preparation

In this study, the extraction of starch from oats with thin alkali and enzymatic treatment was introduced. The physicalchemical properties of oat starches were analyzed. The influence of the components of the oat flours on preparation of resistant starch was probed into. The preparation and digestibility of resistant starches were discussed. The results were as follows: The optimum conditions of starch extraction were discussed.The results showed that under the ratio of liquid to solid 10:1, pH 10, time 3 h and temperature 35℃, the starch content was 78.21%, and the protein residue in the starch was the lowest, down to 1.30%. After enzymatic treatment by adding neutral proteinase, the protein content significantly decreased. Under the conditions of temperature 45℃, the ratio of solvent to material 6:1, pH 7 and enzyme addition 400 U/g, the protein residue in the starch could be reduced to 0.65%.The Dingyou No.4 and Baiyan No.2 starch particles were small but had a wide diameter of 1.68~29.30μm and 1.76~33.27μm, respectively, assuming elliptic and polyhedral type, clear polarization cross. The X-ray apectra of both oat starches were of A-type; the total amylose content of the starches was 22.52% and 22.45%, respectively; the pasting temperature was 87.6℃and 87.8℃, respectively. Oat starches retrogradation was slower than corn starch, and the retrogration volum was 77.71 mL/100mL and 77.45 mL/100mL, respectively.Oat lipids or prolamin could significantly reduce the yield of resistant starch, meanwhile, albumin, globulin or residue protein could improve the yield of resistant starch. Glutelin of Dingyou No.4 oat starch reduced the yield of resistant starch, contrary to Baiyan No.2 oat starch.The optimum conditions of resistant preparation were: starch milk 15%, enzyme addition 1 PUN/g, temperature 65℃for 12 h. The resistant starch content was 13.73%.Resistant starch could significantly slow the rate of starch hydrolysis. While its content increased, the rate of digestion slowed down. Dingyou No.4 resistant starch content was lower than the resistant starch, but the digestion rate of them within the first 120 min were similar, even the digestion rate of Dingyou No.4 resistant starch was lower than the sample within the first 60 min.