Chen Xianghua, Chen Fangman, Sun Shuo, Li Yingwen, Li Yongxing, Mo Hui, Li Zhian, Zhuang Ping
South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China.
Foods. 2022 Sep 5;11(17):2718. doi: 10.3390/foods11172718.
Rice polishing is an important approach to reducing the concentrations of heavy metals in rice, but knowledge of its effect on the Pb and Cd bioavailability in produced rice and the related health risk remains limited. In this study, the effects of rice polishing on the bioaccessibility (BAC) and bioavailability (RBA) of Pb and Cd in rice are assessed using an in vitro method and an in vivo mouse bioassay. The Pb removal rate in brown rice (40%), lightly processed brown rice (62%), germinated rice (74%), and polished rice (79%) gradually enhanced with an increase in the polishing degree, while Cd was difficult to remove by polishing. The Pb and Cd BAC in germinated rice was the highest, while that in brown rice was the lowest. The polished rice Pb and Cd RBA in the liver and kidneys were significantly higher than those in the brown rice group. The Pb RBA in the livers and kidneys in the polished rice group was 26.6% ± 1.68% and 65.3% ± 0.83%, respectively, which was 1.6- and 2.6-times higher than that in the brown rice group, respectively. The Cd RBA values in both the livers and kidneys of the polished rice group were 1.3-times higher than those in the brown rice group. Although polishing reduced the total Pb in the polished rice, it was not enough to offset the increase in bioavailability, and its consumption risk was not weakened. This study highlighted the value of the oral-bioavailability-corrected health risk assessment for assessing the influence of rice polishing on Pb and Cd exposure via rice consumption.
大米抛光是降低大米中重金属含量的重要方法，但关于其对所产大米中铅和镉生物有效性的影响以及相关健康风险的了解仍然有限。在本研究中，采用体外方法和体内小鼠生物测定法评估了大米抛光对大米中铅和镉的生物可及性（BAC）和生物有效性（RBA）的影响。糙米（40%）、轻度加工糙米（62%）、发芽米（74%）和精米（79%）中的铅去除率随着抛光程度的增加而逐渐提高，而镉则难以通过抛光去除。发芽米中的铅和镉生物可及性最高，而糙米中的最低。精米在肝脏和肾脏中的铅和镉生物有效性显著高于糙米组。精米组肝脏和肾脏中的铅生物有效性分别为26.6%±1.68%和65.3%±0.83%，分别比糙米组高1.6倍和2.6倍。精米组肝脏和肾脏中的镉生物有效性值均比糙米组高1.3倍。虽然抛光降低了精米中的总铅含量，但不足以抵消生物有效性的增加，其消费风险并未减弱。本研究强调了经口服生物有效性校正的健康风险评估在评估大米抛光对通过食用大米接触铅和镉的影响方面的价值。
