记笔记

Some Physical and Milling Properties of Rice Varieties

Iraj Bagheri Msc¹Mohammadreza Alizadeh²Leila Fonoon³

1. Department of Agricultural Mechanization Engineering,Faculty of Agricultural Sciences,The University of Guilan 2. Department of Agricultural Engineering,Rice Research Institute of Iran(RRII)3. Department of Agronomy and Plant Breeding,Faculty of agricultural Sciences,University of Guilan

摘要：In order to design and optimize rice processing machines,it is important to determine some major physical and milling properties of the paddy varieties.In this study such physical properties as size and shape of the grain,thousand grain mass,bulk density,static coefficient of friction and angle of repose and milling characteristics for five varieties of rough rice namely Tarom,Khazar,Fajr,Nemat,Neda,were determined.The results showed that rough rice of Nemat variety has the highest mean length（11.45mm）,width（2.36mm）,equivalent diameter（3.74mm）,grain volume（27.49 mm3） and surface area（42.13mm2）.The Tarom variety registered the lowest length（9.58mm）,thickness（1.79mm）,equivalent diameter（3.42mm） and volume（21.07mm3）,while the maximum thickness of 1.95mm belonged to Neda variety.The average values of aspect ratio and sphericity for the five varieties tested were 0.22 and 34%,respectively.The highest thousand grain mass（29.90g） was obtained for Nemat variety and the lowest value（21.48g） was for Tarom.The results showed that bulk density for Tarom（511.54 kg/m3） and Nemat（512.99 kg/m3） were not significantly different,but bulk density of Neda（596.38 kg/m3） was significantly different from the other four varieties.Statistical analysis showed that there was no significant difference in the angle of repose among different varieties and the average value of the angle of repose was 29.86o.The highest static coefficient of friction was obtained on mild iron sheet surface（0.572）,followed by rubber（0.536） and galvanized iron sheet（0.368）.In terms of milling properties of the paddy varieties tested,there was a significant difference between some of the tested paddies.The highest broken milled rice was obtained for Nemat variety and the lowest was for Fajr.The results also showed that Nemat variety has the maximum weight of paddy and head brown rice compared to the other varieties.Among the evaluated varieties,Tarom has minimum weight of paddy and brown rice.The brown rice paddy weight ratio as a measure of milling recovery was not significantly different in the tested varieties.The results of this research showed that the rice varieties were significantly different in terms of thousand grain mass,bulk density,static coefficient of friction and all milling properties,but there was no significant difference in angle of repose.

关键词：

Physical properties; milling properties; paddy varieties;

会议名称：

2010国际农业工程大会

会议时间：

2010-09-18

会议地点：

中国上海