Studies On The Mechanical And Rheological Properties Of Brown Rice And Cooked Rice And Discuss Of Application

The mechanical Theological properties of agriculture is the theory evidences of designing relative processing machine and technique, which can provide new approach and optimal parameter for decreasing mechanical damnification during the process of harvesting, processing, storing and shipping, controlling quality, empoldering new consumption and valuing quality. At present, although there are some reports about the mechanical Theological properties of agriculture, bnt the majority of these studies were on soybean, wheat, com , the study on brown rice was little especially in our country .In other countries the studies only focus on the outside factors. The study on the effect of quality characteres of brown rice on the mechanical Theological properties was not seen. The study on viscous elasticity of the cooked rice was lack, In the past we only depend on the expert's taste-test to define taste characteres of brown rice, which is not enough. So this study can perfect and remedy the preceding , provide reliable theorial evidences for rice processing .improving quality and identifying quality.By means of theoretic analysis and experiment research, the mechanical Theological properties of brown rice and cooked rice were studied. Supposed rice as sphere, the image recognizition method was used to pick up the size of three axises, utilizing formula of curvature radius to deduce the curvature radius of rice on the contacting when it was compressed by flat. Hertz contacting theory was used to analyze rice extrusion equation and stress distribution on contacting side, and deduce rice compression elastic modulus. Shear theory was used to analyze stress distribution on double cutting of brown rice and cooked rice. The Theological model was analyzed and relaxation properties parameters were distinguished by Z transformation. The rice compression mechanical properties, shear mechanical properties and stress relaxation properties were studied by experiments, and the value of compression mechanical properties indexes including elastic modulus,compression failure energy, compression failure force, compression failure stress were obtained, the value of shear mechanical properties indexes including toughness, shear failure energy, shear failure force, shear failure stress were obtained, the value of stress relaxation properties indexes including number of Maxwell cell , relaxation modulusrelaxation time were also obtained et .The effect of parameters including moisture content, loading rate and varieties of brown rice on compression properties indexes, shear properties indexes and stress relaxation properties indexes were studied.The regression equation of influencing factors on mechanical indexeswas established by multivariate regression and multivariate stepwise regression to forecast and control mechanical damnification during processing. In order to evaluate rice taste quality, the shear and relaxation properties of cooked rice were studied. The mechanical rheological properties indexes subject to cooked rice quality properties inclding rigidity , shear failure energy, shear failure force and force relaxation parameter of cooked rice were obtained. The effect of quality character of brown rice on the mechanical rheological properties of cooked rice was studied. The regression equation was established by multivariate stepwise regression to evaluate taste quality of brown rice.