Study On Primary Indicators Of Quality Assessment For Brown Rice

In order to study the impact of major quality indicators on brown rice quality, two kindsof japonica brown rice and indica brown rice are used as the experimental samples, differentcontent of immature grain and broken grain are added to sound particles to study the impactof immature grain rates and integrity brown rice on physical quality, processing quality,cooking quality, eating quality of brown rice, and identify key indicators to evaluate thebrown rice quality.The results showed that（1）With the increased rate of immature grain bulk density and mass of1000grains ofthe brown rice gradually decreased with varying degrees, with the decreased ratio of wholebrown rice, bulk density drop slowly. Compared with indica brown rice, the downward trendof japonica brown rice is more obvious, cause the structure of indica rice is more loose. Incase of similar water content, bulk density of japonica brown rice is higher, under theconditions of the same volume size, the collective of longer grain have more space among theunion, it only accommodate less grain. So the grain length and bulk density have a significantnegative correlation.（2）As the immature grain rates increases and the whole brown rice rate decrease, thebulk density of brown rice get lower, rough out the white rate and head rice yield graduallydecreased, the broken rice rate went up. However, the rough out the white rate declined slowly,while the head rice yield declined obviously. Under the same milling conditions, comparedwith japonica brown rice, the head rice yield of indica brown rice is lower, while thebroken-rice rate is higher. Both the rough out the white rate and head rice yield have asignificant negative correlation with length of rice，and the broken rice rate has a significantpositive correlation with length of rice.（3）With the increase of immature grain content of brown rice which means bulkdensity brown rice get lower, dry matter in cooking residual of both japonica rice and indicarice increased gradually, Following the decrease of water uptake ratio and volume expansionratio of rice; with the decrease of sound grain content of brown rice, dry matter in cookingresidual of both japonica rice and indica rice increased gradually, while volume expansionratio of rice get declined, and the change of water uptake ratio is not significant. comparedwith japonica brown rice, dry matter in cooking residual, water uptake ratio and volumeexpansion ratio of indica rice is higher.（4）With the increase of immature grain content of brown rice, the hardness, elasticity,chewiness decreased progressively, cohesiveness of rice don’t have obvious change. Score ofeating test decreased, the appearance of structure, odor, color, palatability variation are worse,with the sound grain rate increased, the hardness, elasticity and chewiness decreased. Riceeating score are highest at about5percent of broken rice content, this phenomenon indicatethat appropriate content of broken rice could promote gelatinization of rice, and enhance thetaste.