Inorganic arsenic removal in rice bran by percolating cooking water

- Rice bran contains very high levels of inorganic arsenic (i-As) at around 1 mg/kg.
- Rice bran i-As removal method based on the near boiling water technology.
- Novel approach that enables up to 96% i-As removal from rice bran.
- i-As removal technique with minimal impact on rice bran nutritious aspects.

Rice bran, a by-product of milling rice, is highly nutritious but contains very high levels of the non-threshold carcinogen inorganic arsenic (i-As), at concentrations around 1 mg/kg. This i-As content needs to be reduced to make rice bran a useful food ingredient. Evaluated here is a novel approach to minimizing rice bran i-As content which is also suitable for its stabilization namely, cooking bran in percolating arsenic-free boiling water. Up to 96% of i-As removal was observed for a range of rice bran products, with i-As removal related to the volume of cooking water used. This process reduced the copper, potassium, and phosphorus content, but had little effect on other trace- and macro-nutrient elements in the rice bran. There was little change in organic composition, as assayed by NIR, except for a decrease in the soluble sugar and an increase, due to biomass loss, in dietary fiber.