Cooking rice in excess water reduces both arsenic and enriched vitamins in the cooked grain

Abstract

This paper reports the effects of rinsing rice and cooking it in variable amounts of water on total arsenic, inorganic arsenic, iron, cadmium, manganese, folate, thiamin and niacin in the cooked grain. We prepared multiple rice varietals both rinsed and unrinsed and with varying amounts of cooking water. Rinsing rice before cooking has a minimal effect on the arsenic (As) content of the cooked grain, but washes enriched iron, folate, thiamin and niacin from polished and parboiled rice. Cooking rice in excess water efficiently reduces the amount of As in the cooked grain. Excess water cooking reduces average inorganic As by 40% from long grain polished, 60% from parboiled and 50% from brown rice. Iron, folate, niacin and thiamin are reduced by 50–70% for enriched polished and parboiled rice, but significantly less so for brown rice, which is not enriched.

Graphical Abstract

Keywords:

• Rice
• arsenic
• inorganic arsenic
• iron
• cadmium
• washing
• cooking
• folate
• niacin
• thiamin

ORCID

Patrick J. Gray http://orcid.org/0000-0002-8248-2749