Extraction Of Rice Starch By The Enzyme Method Of Protease And Study On The Preparation Of Rice Starch Microspheres

Rice is one of the most important grain crops, in rice grains more than 80% of their weight is starch. Rice starch has been widely used in food etc. industry because of its unique physicochemical characteristics, how to effectively utilize rice, especially its starch, is the focus for people to research recently.Using rice from Heilongjiang Wuchang as material and builded the method that neutral protease extract rice, the characteristic of starch is affected greatly by protein residual in starch. The purification of starch to remove the protein, therefore, is one of the main factors for its application. Using the protein residual in starch as response variable, the five variables:ratio of rice flour to water, pH of solution, enzyme amount, enzyme hydrolytic temperature and enzyme hydrolytic time was investigated by single and orthogonal experiment. The optimum condition as follows:the ratio of rice flour to water is 1:6, pH of solution is 7.5, enzyme amount is 0.7%, and enzyme hydrolytic is temperature 50℃, time 8h. The results of enzyme method showed that the extraction rate of protein was 0.41%.Rice starch was taken as raw materials, mix acid (citric acid and acetic anhydridethe)as the cross-linking agent, Span60 as the emulsifying agent and the plant oil as the organic phase, and starch micrspheres were synthesized by the way of reversed-phase emulsion polymerization, using the average particle size of rice starch micrspheres as an evaluation index.The single element and orthogonal experiment showed the preparation of rice starch micrspheres reaction optimum condition as follows:the concentration of starch is 20%,ratio of organic phase and aqueous phase is 8 : l,the quantity of emulsifying agent is 0.8g/100mL oils and cross-linking agent is 6mL/100mL oils. Its average size is 4.25μm.Under the detection of the rice starch microspheres by the IR, SEM surveying instrument, the results showed:Compared the infrared spectrogram of rice starch microspheres with rice starch rice starch was cross-linked with mix acid (citric acid and acetic anhydridethe)which as the cross-linking agent, the results proved:rice starch had cross-linked with mix acid pretty good.The structure of rice starch microspheres and rice starch were analyzed by scanning electron microscopy (SEM), the results showed: rice starch microspheres were round and smooth, the particle diameter of themicrospheres is uniformity.The adsorption capability of starch microspheres for the methylene blue and peppermint oil was studied. And builded the method that adsorption was fastly measured:Ultraviolet Spectrophotometer.The adsorption capability of starch microspheres for the methylene blue was studied, through the experiments of starch microspheres for the adsorption of methylene blue optimum conditions are:the concentration of methylene blue is 10pμg/mL, adsorption time is 6h. Under this condition, the adsorption capacity for methylene blue is 1.71mg/g, adsorption efficiency is 86.03%.The adsorption capability of starch microspheres for the peppermint oil was studied, through the experiments of starch microspheres for the adsorption of peppermint oil optimum conditions are:the concentration of peppermint oil is 4%, adsorption time is 3h. Under this condition, the adsorption capacity for peppermint oil is 34μL/g, adsorption efficiency is 86.75%. Compared with rice starch and found that absorption and adsorption efficiency were increased. The results showed:starch microspheres in adsorption are on the superiority.