Discussion of Influence of parboiling in milling rice yield and head rice yield

Document Type : Research Paper


Assistant professor of Mechanical Engineering of Biosystems


The rice crack is the most significant conversion drop in our country. Parboiling along with gelatinizing rice starch and filling the cracks of rice leads to increased rice grain resistance and finally, its crack percentage significantly decreases and the conversion coefficient and the percentage of healthy rice increases as well. Recently, the use of microwave in parboiling operation has been taken into consideration by researchers. In this study, the effect of four cultivar factors in two levels (Shroodi and Hashemi), the soaking temperature in two levels (60 and 70 C), the microwave power in two levels (600 and 900 W) and the duration of heating in two levels (2 and 4 min) on conversion coefficient and the percentage of healthy rice were examined. The results indicated that with increasing the soaking temperature, the conversion coefficient increases significantly. The conversion coefficient in Shiroodi cultivar was significantly higher than Hashemi cultivar. With increasing the microwave power, the percentage of healthy rice increased significantly. The highest conversion coefficient and the percentage of healthy rice in both cultivars were related to the soaking temperature of 60 C, the power of 900 W and the heating duration of 2 min.


Main Subjects

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