Paper Details

Milling characteristics of rice grains as affected by paddy mixture ratio and moisture content

Sayed Hossein Payman, Iraj Bagheri, Hemad Zareiforoush

DOI: https://dx.doi.org/10.12692/ijb/4.2.87-97

Int. J. Biosci. 4(2), 87-97. January, 2014. (PDF)

Abstract:

The paper presents results of study on the effects of moisture content and paddy mixture ratio (defined as the mass percentage of paddy accompanied with brown rice when arriving into rice whitener machine on milling characteristics of rice grains. The experiments were conducted at four levels of moisture contents (MC), namely 8, 10, 12 and 14% (w.b.) and five levels of paddy mixture ratio (PMR), including 2, 3, 4, 5 and 6%. The milling characteristics were determined in terms of fissured kernels (FK), Head Rice Yield (HRY), whiteness percentage (WP) and whiteness index (WI). The results revealed that as PMR increased from 2 to 6%, the values of FK and WP decreased, whilst HRY decreased by increasing PMR from 2 to 6%. At all of the evaluated PMRs, the values of HRY, WP and WI decreased by decreasing MC from 14 to 8% (w.b.). It was observed that with decreasing MC from 14 to 10% (w.b.), the number percentage of FK decreased and then the further decrease in MC from 10 to 8% (w.b.) caused the FK to increase. It was concluded that in the whitening process, if rice grains arrived into the whitener with higher levels of PMRs, higher values of HRY could be obtained for the product. This is also accompanied with lower WPs.