Study On The Maximum Content Of Hulled Rice On Paddy Quality

With the development of agricultural mechanization, husked rice in paddy content increases by years. The national standard, husked rice in paddy no more than 2%, is no longer applies to the current purchase and production of paddy. Therefore, through questionnaires and telephone inquiries, investigated the content of husked rice in paddy in different regions, and analyze the cause of husked rice in paddy. At the same time, as a control group, the rice without husked rice in paddy will compare with the rice of different husked rice content, which storage in the high temperature and humidity, and study the storage reservoir quality, processing quality, cooking quality, pasting properties, texture and eating quality characteristics of the rice with different husked rice. Using correlation analysis and difference to analysis the effect on rice quality with different husked rice. Meanwhile, under premise of does not affect the rice quality, determine the maximum value of husked rice in paddy. In this paper, the main conclusions are as follows:(1) Since the different climate and environmental in north and south, the ways of cultivation, harvesting, drying are all different, with the different content of husked rice in paddy in different region. Currently, content of husked rice in paddy more than 2%,which is the national standard, is occupied 27% in the investigation. Using combines-harvester and drying is the mainly reasons that result on the husked rice in paddy.(2) During the storage, the variation trend of storage quality in medium to short-grain nonglutinous paddy and long-grain nonglutinous paddy is basically same. During the storage, the moisture and MDA falling, fatty acid is increasing in the storage time, while reducing sugar and POD are increased at first and then decreased. Wherein, when the content of the husked rice in short-grain nonglutinous paddy more than 8%, the variation of moisture and fatty acid is more than the control group. Variation of reducing sugar and MDA, which the husked rice in short-grain nonglutinous paddymore than 6%, is quicker than the control group. When the content of the husked rice in short-grain nonglutinous paddy more than 2%, the variation of POD is more than the control group. When the content of the husked rice in long-grain nonglutinous paddy more than 6%, the variation of fatty acid, reducing sugar and POD is more than the control group.(3) During the storage, the variation trend of processing quality in medium to short-grain nonglutinous paddy and long-grain nonglutinous paddy is basically same. During the storage, the milled head rice yield and milled rice yield falling, while broken milled rice yield is increasing in the storage time. Wherein, when the content of the husked rice in short-grain nonglutinous paddy more than 4%, the variation of milled head rice yield and milled rice yield is more than the control group. Variation of broken milled rice yield, which the husked rice in short-grain nonglutinous paddymore than 2%, is quicker than the control group. When the content of the husked rice in long-grain nonglutinous paddy more than 2%, the variation of milled head rice yield and broken milled rice yield is more than the control group. Variation of milled rice yield, which the husked rice in short-grain nonglutinous paddymore than 2%, is quicker than the control group.(4) During the storage, the variation trend of cooking quality in medium to short-grain nonglutinous paddy and long-grain nonglutinous paddy is basically same. During the storage, the solids of rice, pH and iodine blue value are decreasing, while water absorption of rice is increasing in the storage time. When the content of the husked rice in paddy more than 4%, the variation of water absorption of rice and iodine blue value is more than the control group. When the content of the husked rice in paddy more than 6%, the variation of pH and the solids of rice is more than the control group. During the storage, generally, when the content of the husked rice in paddy more than 4%, the variation of paddy pasting properties is more than the control group. During the storage, generally, when the content of the husked rice in paddy more than 6%, the variation of paddy textural properties is more than the control group. During the storage, sensory score is descreasing. When the content of the husked rice in paddy more than 4%, the variation of short-grain nonglutinous paddy pasting properties is more than the control group. When the content of the husked rice in paddy more than 6%, the variation of long-grain nonglutinous paddy pasting properties is more than the control group.(5) Moisture, milled head rice yield and milled rice yield are significantly correlated with content of husked rice in short-grain nonglutinous paddy. Fatty acid and broken milled rice yield are positive correlated with content of husked rice in short-grain nonglutinous paddy. POD, MDA and sensory score are negative correlated with content of husked rice in short-grain nonglutinous paddy. Moisture and milled head rice yield are significantly correlated with content of husked rice in long-grain nonglutinous paddy. Fatty acid and broken milled rice yield are positive correlated with content of husked rice in long-grain nonglutinous paddy. Reducing sugar and sensory score are negative correlated with content of husked rice in long-grain nonglutinous paddy.(6) Using ANOVA analyses the difference among content of husked rice and storage quality, processing quality, sensory score, the results shows that there are quite difference among husked rice and storage quality, processing quality, sensory score. Comprehensive analysis, husked rice in short-grain nonglutinous paddy should not exceed 6%, while husked rice in long-grain nonglutinous paddy should not exceed 4%...