Ministry of Education (MOE) Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou, People's Republic of China.
J Agric Food Chem. 2012 Feb 22;60(7):1871-9. doi: 10.1021/jf205025b. Epub 2012 Feb 9.
Rice is the staple food for more than half of the world's population and, hence, the main source of a vital micronutrient, zinc (Zn). Unfortunately, the bioavailability of Zn from rice is very low not only due to low content but also due to the presence of some antinutrients such as phytic acid. We investigated the effect of germination and Zn fortification treatment on Zn bioavailability of brown rice from three widely grown cultivars using the Caco-2 cell model to find a suitable fortification level for producing germinated brown rice. The results of this study showed that Zn content in brown rice increased significantly (p < 0.05) as the external Zn concentrations increased from 25 to 250 mg/L. In contrast, no significant influence (p > 0.05) on germination percentage of rice was observed when the Zn supply was lower than 150 mg/L. Zn fortification during the germination process has a significant impact on the Zn content and finally Zn bioavailability. These findings may result from the lower molar ratio of phytic acid to Zn and higher Zn content in Zn fortified germinated brown rice, leading to more bioavailable Zn. Likewise, a significant difference (p < 0.05) was found among cultivars with respect to the capacity for Zn accumulation and Zn bioavailability; these results might be attributed to the difference in the molar ratio of phytic acid to Zn and the concentration of Zn among the cultivars evaluated. Based on global intake of Zn among the world population, we recommend germinated brown rice fortified with 100 mg/L ZnSO(4) as a suitable concentration to use in the germination process, which contains high Zn concentration and Zn bioavailability. In the current study, the cultivar Bing91185 fortified with Zn through the germination process contained a high amount as well as bioavailable Zn, which was identified as the most promising cultivar for further evaluation to determine its efficiency as an improved source of Zn for target populations.
大米是全球一半以上人口的主食，因此也是锌（Zn）这种重要微量营养素的主要来源。遗憾的是，大米中的 Zn 生物利用率不仅因为含量低，还因为存在植酸等抗营养物质而非常低。我们采用 Caco-2 细胞模型，研究了发芽和 Zn 强化处理对三种广泛种植的糙米中 Zn 生物利用率的影响，旨在找到一个合适的强化水平，用于生产发芽糙米。本研究结果表明，随着外部 Zn 浓度从 25 增加到 250 mg/L，糙米中的 Zn 含量显著增加（p<0.05）。相比之下，当 Zn 供应低于 150 mg/L 时，对大米发芽率没有显著影响（p>0.05）。在发芽过程中进行 Zn 强化对 Zn 含量和最终 Zn 生物利用率有显著影响。这些发现可能是由于较低的植酸与 Zn 的摩尔比和强化发芽糙米中较高的 Zn 含量导致更多的 Zn 更具生物可利用性。同样，不同品种之间在 Zn 积累能力和 Zn 生物利用率方面也存在显著差异（p<0.05）；这些结果可能归因于评价品种之间的植酸与 Zn 的摩尔比和 Zn 浓度不同。基于全球人口对 Zn 的摄入量，我们建议在发芽过程中使用 100 mg/L ZnSO4 强化发芽糙米，这是一种合适的浓度，可用于强化过程，因为其含有高浓度的 Zn 和高生物可利用率的 Zn。在本研究中，通过发芽过程强化 Zn 的 Bing91185 品种含有大量且生物可利用的 Zn，被认为是最有前途的品种，可进一步评估其作为目标人群 Zn 改良来源的效率。
