Bioaccessibility of arsenic in various types of rice in an in vitro gastrointestinal fluid system

Abstract

Rice can be a major contributor to dietary arsenic exposure because of the relatively high total arsenic concentration compared to other grains, especially for people whose main staple is rice. This study employed in vitro gastrointestinal fluid digestion to determine bioaccessible or gastrointestinal fluid extractable arsenic concentration in rice. Thirty-one rice samples, of which 60 % were grown in the United States, were purchased from food stores in New York City. Total arsenic concentrations in these samples ranged from 0.090 ± 0.004 to 0.85 ± 0.03 mg/kg with a mean value of 0.275 ± 0.161 mg/kg (n = 31). Rice samples with relatively high total arsenic (>0.20 mg/kg, n = 18) were treated by in vitro artificial gastrointestinal fluid digestion, and the extractable arsenic ranged from 53 % to 102 %. The bioaccessibility of arsenic in rice decreases in the general order of extra long grain, long grain, long grain parboiled, to brown rices.

Keywords:

• Rice
• arsenic
• in vitro gastrointestinal fluid digestion

Acknowledgment

Support provided by a U.S. Department of Education Title V grant for institutional development to John Jay College and PSC-CUNY grants (60027-35-36 and 68535- 00 37) to YH are gratefully acknowledged. Dr. David Locke at Queens College, the City University of New York, was thanked for his comments.