Modification Of Buckwheat Starch And Application In Moisturizing Lotion

Buckwheat, as a kind of grain, is widely planted in China, starch is a major componentof buckwheat, but because of the defects of its own properties, its application is greatlylimited. In this paper, we prepared pre-gelatinized buckwheat starch, micronized buckwheatstarch and granular-cold-water-soluble(GCWS) buckwheat starch, through the physicalmodification methods, analysed the impacts of modification on physicochemical properties ofbuckwheat starch. Finally we added buckwheat starch to moisturizing lotion, aimed to providetheoretical basis for buckwheat starch’ applications. The results showed that:(1) By using ethanol-alkali method to prepare GCWS buckwheat starch, the impact ofreaction temperature on the solubility of GCWS buckwheat starch was significant; Theappropriate preparation conditions were on the reaction temperature of70℃, ethanolconcentration of80ml/100ml,reaction time of80min, alkali（NaOH）concentration of10.5g/100ml. Under these conditions the solubility of the product was up to98.24%.(2)The pre-gelatinized buckwheat starch particle has cracked, microcrystalline structuredisappeared, the polarization cross can’t be observed, but the crystallinity is still18.72%; theexpansibility and water absorption was improved significantly. There was minor variation instarch composition between pre-gelatinized buckwheat starch and buckwheat starch. Thethermal stability and retrogradation became worse. The transparency increased slightly. Thefreeze-thaw analysis of water rates decreased.The micronized buckwheat starch particle was more homogeneous than buckwheatstarch; The crystallinity was very low(1.62%); The polarization cross of part of particles canstill be observed; The solubility and expansibility raised, and the water absorptionsignificantly increased; The amylose content increased, so the blue value became larger. Thethermal stability and anti-aging ability of starch paste was improved, and transparency wasvery low. The freeze-thaw analysis of water rates became lower; The stability ofretrogradation decreased.The GCWS buckwheat starch particle was mostly present as elliptical, and there washole on its surface; The crystallinity significantly reduced to6.25%, the polarization crosscould not be observed; The GCWS buckwheat starch was basically soluble completely in water; The water absorption increased, the same to the amylose content; Also the starchpaste has good thermal stability, high transparency and poor freeze-thaw stability.(3) The emulsifier optimal proportion of buckwheat starch moisturizing lotion ismonoglyceride3%, Tween-201.2%, xanthan gum0.4%; The impact of Tween-20andxanthan gum on the property of buckwheat starch moisturizing lotion was significant; Theoptimum emulsifying conditions were on the emulsifying temperature of80℃, emulsifyingtime of15min, the micronized buckwheat starch addition of1%. Under these conditions, theproduct has excellent sensory quality, stable physicochemical properties, furthermore themoisturizing efficiency could reach to20.64%.