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

Authors: Chen, Guoying; Lai, Bun-Hong; CHEN, TUANWEI - Fujian Agricultural & Forestry University; MAO, XUEFEI - Chinese Academy Of Agricultural Sciences

Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/5/2020
Publication Date: 6/2/2020
Publication URL: https://handle.nal.usda.gov/10113/7019759
Citation: Chen, G., Lai, B., Chen, T., Mao, X. 2020. Brief soaking at above-gelatinization temperature reduces inorganic arsenic in cooked rice. Cereal Chemistry. https://doi.org/10.1002/cche.10304.
DOI: https://doi.org/10.1002/cche.10304

Interpretive Summary: Rice contains ten times more inorganic arsenic (iAs), a notorous carcinogen, than other grains and foods of plant origin. To reduce iAs in cooked rice, above-gelatinization-temperature soaking was explored for the first time to reduce iAs. On average, 80 ' soaking in 10 times of water for 10 min reduced 38.2% iAs from white rice. This method requires no special equipment, so can be implemented in a family kitchen and followed immediately by traditional east Asian cooking using a rice cooker.

Technical Abstract: Rice contains ten times more inorganic arsenic (iAs), a class 1 non-threshold carcinogen, than other grains and foods of plant origin. 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 cooking in percolating 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. In this work, above-gelatinization-temperature soaking was explored for the first time to reduce iAs in cooked rice. For white rice, 80 ' soaking with W/R 10 for 10 min reduced iAs by up to 48.4%. A soaking protocol was developed for the public to practice in a family kitchen that on average reduced iAs in white rice (n=13) by 38.2%.