Research On Properties And Effects Of Natural Fermented Rice Flour And Rice Starch

Rice noodles, vermicelli and other traditional starch gel food was love by the vast number of consumers. Natural fermentation could improve the texture, taste and flavor of rice as raw material, in order to explore the variation characteristics of rice flour in the course of natural fermentation. The study focused on physical and chemical properties, pasting properties, infrared spectrum characteristics and gel texture of rice flour products during three kinds of rice fermentation process, to the following conclusions:The crude protein content of indica Rice(fermentedld～5d),decreased from 9.58% to 7.47%(P<0.05); the glutinous rice’s content decreased from 7.5% to 6.65%(P<0.05); the japonica rice’s, decreased from 7.89% to 4.73%. The change from indica rice and japonica rice fat content were not significant (P>0.05), fat content of glutinous rice(fermentedld～5d),decreased from 5.5% to 3.4%(P<0.05); indica rice, japonica rice, glutinous rice and their ash content in the fermentation(fermented1～7d) decreased to 0.12%、0.19% �'� 0.24%; their solids content decreased to0.025g/mL、0.018g/mLand0.005g/mL; their pH were 4,3.8,4.3 in 9d.The amylose content of indica rice and japonica rice were 27.32%and20.36% natural fermentation had no significant effect on amylose content. Fourier Transform Infrared Spectrometer was concluded that there were no new functional groups and compounds in the natural fermentation process.The ratio of crystalline structure and non crystalline structure of glutinous rice starch was the highest, and indica Rice’s ratio was the lowest. The trend was increased during the fermentation time increased.Peak time and pasting temperature of three kinds of rice starch during fermentation process, along with the growth of fermentation time, showed the downward trend. Breakdown value and peak viscosity showed the trend of first increasing and then decreasing (P<0.05). The peak viscosity of indica Rice was the smallest (3465, fermented 3d), with the growth of fermentation time, To, the enthalpy of the paste was on the rise (P< 0.05), and Tp showed a downward trend (P< 0.05). Indica rice’s To, Tp and Tc were the highest, the highest enthalpy value of glutinous rice was 5.34J/g. Indica rice is more suitable for making Rice noodles than japonica rice and glutinous rice.And chewing value with fermentation time increased by indica rice production value Rice noodles hardness (P<0.05),the change of recovery was not significant (P>0.05). The loss rate of rice flour cooking decreased first and then increased during fermentation time, after the first time, the compound water showed a trend of increasing first and then descending with the fermentation time, the cooking characteristics of rice flour with natural fermentation 72h was the best. Natural fermentation time had a very significant positive correlation with hardness, chewiness (0.989**,0.972**), hardness and chewiness degree were positively correlated (0.978**),3 days of fermentation of rice flour sensory score up to 81.6 that have a good taste.