The vitamin concentration of white, parboiled and brown rice is
given in Table 1. As expected, due to the milling the vitamin
concentration in white rice is much lower than in brown rice,
meaning losses about 85.8% for B1, or retention of only 14.2% of the
brown rice nutritional value. In respect very high losses 33.8% for
B2, 73.8% for B3, 25.9% for B5 and 71.4% for B6 were observed for the
other vitamins due to milling. The vitamin concentration in parboiled
ricewas slightly higher than that of the white rice (p < 0.05).
The parboiled rice was cleaned and milled like the white rice, thus
its vitamin concentration should be lower than that of brown rice.
However during the parboiling process a part of the vitamins is
diffused from the vitamin-rich outer bran layer to inbound due to
vitamin concentration gradient, especially vitamins B1 and B6.
Similar results of vitamin concentration and losses during milling
have been reported by Dexter (1998), Kunze and Wratten (1985)
and USDA Nutrient Data Laboratory (2005).