The Studies On Edble Quality Of Quick-cooking Rice

Based on broken Xingyang hybrid rice flour as the main raw material and glutinous riceflour, food additives and micronutrient, using extrusion technology to produce quick-cookingrice was studied in this paper. The paper was mainly researched the effects of the twin-screwextrusion processes, the addition of other ingredients and food additives on the edble qualityof quick-cooking rice.Firstly, sensory evaluation of quick-cooking rice as the target parameters, the effects ofmaterial moisture content, the screw speed, barrel temperature and feed speed impact on thequality of the recombinant rice was studied, and the best response value of each factor wasdetermined. Based on the single factor experiment, material moisture content, the screw speed,barrel temperature were selected to do Box-Benhnken central composite design. The responsesurface analysis was used to optimize processing parameters with the sensory analysis as themain target. The optimal extruding parameters were: the material moisture content was26%,the Ⅲ zone temperature was107℃, the barrel speed was14HZ, the feed speed was10HZ.The sensory evaluation was about78marks at the optimal parameters, and the form ofquick-cooking rice was close to the natural rice.Based on the optimal process parameters, the quick-cooking rice was added themonoglyceride, SE-15, csl-ssl, lecithin, sodium pyrophosphate, complex phosphate as qualityimprovers. The influences of the different additives on the quality of recombinant rice wereanalyzed in this paper. According to the single factor experiment, the experimental date wasanalyzed by combining fuzzy analysis method with orthogonal test, and the result showed thatthe best additive content was obtained, viz. the contents of csl-ssl, SE-15, monoglyceride,sodium pyrophosphate, complex phosphate, lecithin were0.1%,0.45%,0%,0.15%,0%,0.8%.The qualities of quick-cooking rice, made by the optimal formula using extrusion technology,were better than that of native rice, and the cooking time of the sample dropped about onetime than the native rice, and the cooked rice had higher softness, viscoelasticity, goodappearance and also remained their native taste.The edble quality of quick-cooking rice was improved according to the change of theproportion of amylase and protein content by adding glutinous rice flour and wheat flour. Theresults showed that the rice maintained the original brightness, whiteness, flavor, and its tastewas good, softness and appropriate viscosity when adding glutinous rice flour at15%. However, the wheat flour played a blight effect on the recombinant rice quality, so it couldn’tbe as the ingredients of quick-cooking rice.Finally, the effects of extrusion technology on the chemicophysical properties of rice andthe content variation of vitamin B1and B2were studied in the test. Under the extrusionprocess, the loss of the vitamin B1and B2were53.8%and19.4%, which decreased afteradding the additives. According to the Scanning Electron Microscope, it could be seen that themicrostructure of rice had tremendous change, the surface structure just like porous. And theporous structure became bigger with adding the additives, but the surface was more smooth.The raw rice, recombinant rice and high quality commercial rice were analyzed by the sensoryevaluation and texture analyzer, each edble quality of recombinant was close to the highquality commercial rice.