The Properties Analysis And Application Of Buckwheat Starch And Its Modified Starches

The main component of buckwheat is starch. However, due to some defects ofbuckwheat starch itself, its application is limited. Recently, the demand of natural cosmeticsgrows day by day, while the application of buckwheat starch into cosmetic industry is rare. Toexpand the application of buckwheat starch, especially in the field of cosmetics, this paper,firstly, studied the physicochemical difference between buckwheat starch and six othercommon starches, and pointed out the advantages and disadvantages of buckwheat starch;secondly, by studying the physicochemical characters of buckwheat starch and its modifiedstarch, the effect of modification treatment on buckwheat starch is cleared; finally, optimizedthe formula and manufacturing conditions of buckwheat starch facial mask. The results arelisted below:The buckwheat starch particles are irregular polygonal sharps. They have an X-raydiffraction pattern of A and the crystallinity is25.97%. The amylase content of buckwheatstarch is relatively high among potato starch, but lower than that of rice, wheat and cornstarch. Buckwheat starch has high value of peak viscosity and setback, which leads to a highaging speed. It has relatively poor transmittance, anti-retrogradation and freeze-thaw stability.The buckwheat starch has a good solubility and high water absorption and low oil absorptionproperty.Prepared by alcoholic-alkaline treatment, granular cold-water-soluble starches wereobtained. Their ratio of starch components was improved-higher than buckwheat starch andother two modified starches. The cold-water-soluble starches had high light transmittance andwere stable after24h rest. Comparing to the original starch, granular cold-water-soluble starchhad similar X-ray diffraction pattern, lower crystallinity, higher solubility, swelling power,water/oil absorption.The particle size of micronized buckwheat starch was more even. The crystallinity wasvery low. X-ray diffraction pattern showed a significant change. The micronized starch hadmore amylase, higher solubility, water/oil absorption and lower swelling power. In addition, the light transmittance of starch paste was lowered, but better freeze-thaw stability wasobtained.The pre-gelatinized buckwheat starch particles had cracked. The amylase contentdropped. And the peak viscosity was improved comparing to the original buckwheat starch.The pre-gelatinized buckwheat starch had significantly higher water/oil absorption, solubilityand swelling power. In addition, the light transmittance and freeze–thaw stability of starchpaste was improved.The best facial mask quality is obtained when the following additions are used:2%monoacyl-glycerol,1.2%Tween-20,1.4%span-60,4%CMC and1%xanthan gum. Theoptimized manufacturing conditions are as following: the temperature of80℃,homogenization time of3min and homogenization speed of3600m/min.The facial mask of micronized buckwheat starch is better than others. When the additionof micronized buckwheat starch is2.5%, its comprehensive score is the highest. According tothe standards, micronized buckwheat starch facial mask is qualified. Its moisture rate is27.189, hardness is21.97%, consistency is259.22g.sec, and viscosity is38.03g.sec.