Research On The Effect Of Raw Material Composition To Product Quality And The Evaluation Method Of Nutritional Rice

The subject use the broken rice as the carrier,use the main components in the raw material as materials to research the effects of raw material composition of the twin screw extrusion process on the product characteristics and use the principal component analysis to establish quality evaluation method to component nutritional rice.Firstly, in order to research the relationship between the indexes, using the RVAto detect the pasting properties of rice flour which add corn starch,rice prote in,dietary fiber and soybean flour before and after extrusion, extrusion products made textu re analysis. The results showed that adding four different levels of raw material will affect pasting eigenvalues of raw materials,and the product RVA viscosity significantly reduced after extrusion.RVA eigenvalues and textural properties of extruded products correlation,th e viscosity of product texture parameters and the pasting parameters of the raw material b efore extrusion were negatively correlated, and there was a significant negative correlation with peak viscosity and low viscosity, but the final viscosity and setback was a significant positive related after squeezing.Secondly,in order to research the residence time distribution of material during twin-screw extrusion process, which added material with different component.Using carbon as a tracer, measured the color of the extrudate with color measurement instrument and the residence time distribution of samples in each group were analyzed.The main results showed that:the raw material component will affect the residence time and the degree of mixing.The initial MRT was 182 second and the initial Pe value was 19.MRT was reduced to173 second and Pe value was reduced to 10 when the adding of corn starch was 25 percent.The MRT prolong to 214,229,212 seconds and the Pe value reached to 31,66 and 29,respectively when 15 percent of rice protein,10 percent of dietary fiber,6 percent of soybean oil were added respectively.The 20 group of orthogonal regression test belongs to the intermediate volume diffusion model.The sequence of effects of variables to MRT was the soybean oil, dietary fiber content, rice protein and the corn starch.At last,in order to guide the quality improvement and new products development of the compound nutritional rice.this research is purposed to establish the quality assessment model of compound nutritional rice, by the means of principal component analysis, based on its physical features.The main results showed that:the 20 selected indicators can be grouped into four main components, reflecting the palatability and cold-properties of the compound nutritional rice, the degree of degradation and gelatinization during extrusion, respectively; the assessment model is tested through the sensory evaluation, which proves the well consistency of the two methods. Principal component analysis can be used as the method for the quality evaluation of component nutritional rice.