The Properties Of Brown Rice Floury Food And Its Application In Extruded Instant Gruel

Brown rice is an important kind of whole grain food,its nutritional values and health function has been widely recognised by domestic and international academic circles. Brown rice contains rich dietary fiber and a variety of function ingredients, so it plays an important role in improving people’s dietary structure and alleviating diseases such as diabetes and high blood pressure. However, because brown rice contains much crude fiber and fat what lead to the existence of poor taste rough,absorption peptic and bad processing quality that finaly limiting the application of brown rice as the stable food and snack food. Extrusion modification is an important physical procesing. A series of physical and chemical changes had taken place in material because the mixture, meshing, kneading, high temperature and high pressure in the process of extrusion.In this study, the effect of materisl properties on extrusion instant gr uel quality was discussed.Final,the law of brown rice extrusion instant gruel quality improvement was obtained so that the selection of raw material in the process of production was guided.The study indicated that the diffierence of different varieties of rice starch was siginificant, the difference of extrusion product quality was siginificant too.The correlatio n between amylose content and water absorption index was positively significant,the water solubility index was significantly negatively correlate with amylose content, the amylose content showed a certain correlation with eapansion ratio,he correlation between the ratio of amylose to amylopectin content and water absorption was positively significant.The quality of extrusion instant gruel made of different amylose/amylopection brown rice misture flour was evaluated,and the correlation on the property of dif ferent amylose/amylopection and the quality of extrusion brown rice instant gruel was also nanlyzed. The results indicate that with the increase of amylose/amylopection,the smooth degree and density of extrusion instant gruel has increased and the number of small holes in the cross section has decreased. The structure of cross section was the most uniform and dense when the mylose/amylopection was 0.256. A totale of 20 volatile compounds of extrusion brown rice instant gruel were identified, the main compounds were aldehydes. The difference of the quality of extrusion brown rice instant gruel of different amylose/amylopection was significant. Whent the mylose/amylopection was 0.256,the score of extrusion brown rice instant gruel was the highest. Correlation analysis showed that the correlations among amylose/amylopection with the expansion rate, rehydration rate of the extrusion instant gruel were negative and significant.Correlation among mylose/amylopection with rehydration time was positive and significant. Correlations among peak viscosity with the thousand kernels weight,expansion rate were significant.The maintain viscosity showed significant correlation with the expansion rate,rehydration rate,rehydration time of extrusion instant gruel.The final viscosity showed significant correlation with the expansion rate,rehydration rate,rehydration time of extrusion instant gruel.The setback showed significant correlation with the rehydration rate,rehydration time,content of solids in the rice water of etrusion i nstant gruel.The correlations among maintain viscosity,final viscosity,setback with TPA properties of extrusion instant gruel were significant.The correlations among peak temperature,terminated temperature with the thousand kernels weight were significant.The initial pasting temperature shower significant corrlation with the content of solids in the rice water.Quality of eight kinds of brown rice extrusion instant gruel were analysed,the correlation among the properity of brown rice flour with the quality of extrusion instant gruel.The results indicated the difference between the eight kinds of extrusion instant gruel was significant.The quality of Japonica brown rice extrusion instant gruel was better than the quality of Indica brown rice extrusion instant gruel.The amylose/amylopection of brown rice was higher,the quality of extrusion instant gruel was worse. A totale of 27 volatile compounds of extrusion brown rice instant gruel were identified,the main compounds were aldehydes.Correlation analysed showe d that the correlations among content of amylse, amylose/amylopection with rehydration rate was significant.The correlation among rehydration rate with breakdown was significant.The correlations among breakdown,final viscosity,setback,pasting temperature w ith rehydration time were significant.The correlations among rehydration time,cohesiveness with initial pasting temperature were significant.The correlations among rehydration rate,rehydration time with peak temperature,terminated temperature were significant. The correlation among resilience with enthalpy was significant.Discussion of the impact of single-factor test parameters for extrusion brown rice instant gruel quality,the results showed that: the extrusion temperature of 100-110℃,moisture content of 31%,screw speed 190r/min, oven temperature 240℃,the evaluation of each quality indexes were better.On this basis,obtained by response surface analusis,the resulats showed:the best production process for extrusion brown rice instant gruel was screw speed 185r/min,extrusion temperature of 100℃,moisture content of 29.22%.