利用体外实验方法评估稻米中镉的生物可给性和健康风险

为了研究稻米中镉(Cd)的生物可给性与稻米理化性质之间的相互关系以及稻米摄入而导致的Cd健康风险,从湖南某些地区采集了16个稻米样品,利用in vitro方法研究了这些稻米中Cd的生物可给性及其人体健康风险。结果表明:在16个样品中,有13个样品的Cd含量超过稻米中Cd的限量标准(0.2 mg·kg-1)。稻米中Cd的溶解态含量及其生物可给性变化较大,胃阶段和肠阶段Cd的溶解态含量范围分别为0.102~1.70 mg·kg-1和0.015~0.249 mg·kg-1,平均值分别为0.698 mg·kg-1和0.103 mg·kg-1,胃阶段和肠阶段Cd的生物可给性的范围分别为56.8%~82.0%和6.62%~15.9%,平均值分别为70.9%和11.1%。模拟肠液中Cd的溶解态含量与稻米的纤维含量之间有显著的相关性。如果不考虑稻米中Cd的生物可给性,所采集的所有稻米样品的摄入都将导致成人和儿童健康风险。如果我们考虑了稻米中的生物可给性,只有31%的稻米样品会对成人产生健康风险,将有50%的稻米样品会对儿童产生健康风险。

Bioaccessiblity of Cadmium in Rice and Its Health Risk Assessment by in vitro Method

Sixteen rice grain samples were collected from Hunan Province in China to investigate the relationship between the bioaccessibility of cadmium (Cd) in rice grains and rice physicochemical properties, and the potential human health risk by dietary exposure to Cd in rice grains. in vitro method was used to model the exposure and digestion by human. Results indicated that 13 out of 16 rice grain samples had Cd concentrations exceeding the standard limits (0.2 mg kg^-1 in food). The concentration of dissolved Cd and therefore its bioaccessibility varied to relatively great extent during the different stages of digestion. The concentration of dissolved Cd ranged between 0.102-1.70 mg kg^-1 with a mean of 0.698 mg kg^-1 in the gastric phase and 0.015-0.249 mg kg^-1 with a mean of 0.103 mg kg^-1 in the small intestinal phase. The Cd bioaccessibility ranged between 56.8%-82.0% with a mean of 70.9% in the gastric phase and 6.62%-15.9% with a mean of 11.1% in the small intestinal phase. Dissolved Cd levels in the small intestinal phase significantly correlated to fiber contents of rice grain. All collected rice grain samples might be considered to pose adults and children to health risks by ingestion, if the bioaccessibility of Cd in rice was not considered. However, only 31% rice grain samples could potentially cause health risks to adults and 50% to children if the bioaccessibility was taken into account