Correlation Analysis Of Milling Degree And Comprehensive Qualities Of Indica Rice

China is one of the main rice producer and consumer in the world,Presently,due to misunderstanding of cosuming and other factors,there is serious excessive processing phenomenon in Chinese rice industry which can lead to huge loss of nutrients and energy,trigger threat of the national food security and do harm to human health.Therefore,advocating moderate processing as well as pursuing the new type of physical property quantitative indication of rice processing degree is the inevitable requirement for the sustainable development of rice processing industry.In this paper,based on the three commercially rice of Indica as Huanghuazhan,Hunan#13,Xing#2 as raw material,the effects of milling degree on the physical and chemical quality?nutritional quality or cooking and eating quality was studied.Then the relationship between the above were discussed.Finally,the nutrient and cooking quality of indica rice with different milling degree were evaluated by AHP.Determining new physical property and quantitative indexes to indicate rice milling degree,and to be used to guide the production of rice.The main results are as follows:The effects of milling degree on the physical and chemical quality?nutritional quality or cooking and eating quality was studied.The results showed that:The grinding rate of three kinds of indica rice treated with varieties milling time was significantly different which increased gradually with the prolong of milling time i,the change was consistent and the trend was obvious.Compared with direct method and dyeing method of strong subjective quickly and objectively,whiteness reflect the degree of grinding of rice quickly and objectively.Peak viscocity,minimum viscocity,breakdown,final viscocity,and pastingtemperature had the same regular changes with the increase of milling time,known as increase of milling degree.Of which peak viscocity,minimum viscocity,breakdown,and final viscocity had increasing change,pasting temperature had decreasing change,and all of these changes were the most obviously within the milling time range from 0 to 30 s.Correlation analysis of physicochemical characteristics under different milling degree of three indica rice show that whiteness,milling of degree,minimum viscocity,breakdown,and final viscocity were significantly positive correlation(P<0.01),and pasting temperature was significantly negative correlation(P<0.01)by correlation analysis.Therefore,RVA pasting properties and whiteness are expected to become new physical property and quantitative indexes to indicate rice milling degree,and to be used to guide the production of rice.The effects of milling degree on the physical and chemical quality of indica rice were studied.The results showed that:There were significant differences in the contents of ash,fat,amylose,total starch,dietary fiber,oryzanol,VBi,VB3 and VB6 in indica rice with different milling degree.With the increase of milling degree,the contents of ash,fat,dietary fiber,oryzanol,VBi,VB3,VB6,sodium,magnesium,potassium,calcium,manganese,iron,copper and zinc of three kinds of indica rice decreased significantly.Amylose and total starch content increased with the increase of milling degree,and all of these changes were the most obviously within the milling time range from 0 to 30 s.Moisture and protein content did not change significantly with the degree of milling.Correlation analysis of physicochemical characteristics under different milling degree of three indica rice showed that there were significant negative correlations between different milling degree with the contents of ash,fat,dietary fiber,oryzanol,VB1,VB3,VB6,sodium,magnesium,potassium,calcium,manganese,iron,copper and zinc(P<0.01),and there was a significant positive correlation between the degree of milling and amylose and total starch content(P<0.01).In summary,milling time for rice reach to 40 s(corresponding to standard two in GB 1354-2009)maybe the point of balance to nutritional and appearance quality.Of which indicate rice milling degree better as the content of fat,oryzanol,dietary fiber,minerals and vitamins showed significant change difference.The effect of milling degree on cooking and eating quality was studied.The results showed that:Milling has a significant effect on the quality of the three kinds of indica rice.With the increase of the degree of milling,the texture and sensory comprehensive scores of the three indica rice samples showed a clear upward trend,and all of these changes were the most obviously within the milling time range from 0 to 30 s.The correlation between the milling degree of the indica rice and the cooking and eating quality showed that:And there was a significant negative correlation with the hardness and viscosity of indica rice(P<0.01).Hardness and viscosity are expected to become new physical property and quantitative indexes to indicate rice milling degree.By AHP analysis,comprehensive assessment on the nutrient and cooking quality of indica rice with different milling degree show that:AHP analysis can be used to compare the proportion of all indexes,as the weight of fat,total starch,dietary fiber,mineral,aoryzanol is relatively higher which can reflect the degree of milled rice mills better.