| The dry method preparation technical conditon of oxidized starch with the corn as raw material and the main properties of oxidized starch was studied in this experiment. The main results were as follows:1. The dry preparation conditions of oxidized starch. At first, Through the joining way of sodium hydroxide, the technology route was established.The factors which affect dry preparation of oxidized starch were studied by single factor experiment, such as: the mole ratio of H2O2/starch, the mole ratio of NaOH/starch, moisture content, reaction temperature and reaction time. Then by using quadratic general rotary design, two regression equations were established in which X was equivalent to code value, Y was equivalent to carboxyl content: Y=0.4867145-1.066668×10-2X1+1.991668×10-2X2+3.666664×10-3 X3 +4.08333×10-3X4+5.749999×10-3X1X2+0.001875X1X3+0.001625X2X3 +0.001625X1X4+0.002625X2X4+4.999992×10-4X3X4-1.655364×10-2X12 -1.267865×10-2X22-9.928644×10-3X32-3.053665×10-3X42Through further optimization and test, we get the optimum parameter of dry preparation of oxidized starch: H2O2/starch mole ratio is 0.219, NaOH/starch mole ratio is 0.144, the moisture content of the system is 27.2%, reaction temperature is 65℃.2. Properties of oxidized starch. Properties of granules and paste of raw corn starch and oxidized starch were compared, the conclusions were as follows:Raw corn starch had bad freeze-thaw stability, but oxidized starch had better freeze-thaw stability, The freeze-thaw stability became better and better as carboxyl content increased.The transmittance of the oxidized starches were larger than that of raw corn starch and the transmittance of the low carboxyl content oxidized starch increased with the increase of carboxyl content, the transmittance of the high...
|
PDF Full Text Request