Milling yield using five different rates of broken and head rice was tested. The samples were arranged to have different amounts of big and small broken kernels in the mass of grains. The size of each fraction of broken grains was established according to the Brazilian Rules of Rice Classification. The paddy sample had 100 g and the brown rice sample had 78 g. The brown rice was milled by adding different proportions of broken kernels to make five treatments as follows: 1) only whole kernels; 2) 6.16 g of big broken kernels and 1.04 g of small broken kernels were used as they appear in the original lot; 3) 3.6 g of big broken kernels and 3.6 g of small broken kernels were added to the whole kernels; 4) 7.2 g of big broken kernels were added to the whole kernels and 5) 7.2 g of small broken kernels were added to the whole kernels. A laboratory mill was used. The classification was made manually. The percentages of broken kernels varied from 3.6% to 7.2% in the fraction of big broken kernels and from 1.04% to 7.2% in the fraction of small broken kernels, respectively. The results showed that, in the milling process using broken kernels in the mass, the head rice yield was significantly higher than when 100% of head kernels were milled.
milling test; rice; broken kernels
