Brief soaking at above-gelatinization temperature reduces inorganic arsenic in cooked rice

Background and objectives Rice contains an order of magnitude higher inorganic arsenic (iAs), a class 1 non-threshold carcinogen, than other terrestrial crops. To reduce iAs in cooked rice, several methods have been proposed such as washing until clear, cooking with high water-to-rice ratio (W/R) then discarding excess water, or continuously percolating near-boiling water. The traditional method practiced by 1.6 billion East Asians, washing and cooking with low W/R until dry, removes only a small percentage of iAs. A new approach was investigated to reduce iAs in cooked rice. Findings Brief (10 min) soaking (W/R 10) at above gelatinization temperature (80 degrees C) reduced iAs in rice by up to 48.4%. A soaking protocol was developed for public use that on average reduced 39.5 +/- 6.6% (n = 12) iAs in non-waxy white rice. Conclusions Brief above-gelatinization-temperature soaking effectively reduces iAs in cooked white rice. Significance and novelty Above-gelatinization-temperature soaking was applied for the first time to cut iAs in cooked rice; thereby chronic iAs exposure and cancer risk can be reduced for rice consumers.

Automated summary

Brief soaking of rice at above gelatinization temperature for 10 minutes can reduce iAs content in rice by up to 48.4%. A soaking protocol has been developed for public use, reducing iAs in non-waxy white rice by an average of 39.5 +/- 6.6% (n = 12). This method effectively cuts iAs in cooked white rice, potentially reducing chronic iAs exposure and cancer risk for rice consumers.