Authors are with Post-Graduation Program on Food Science and Technology, Federal Univ. of Espírito Santo (UFES), Alto Universitário s/n, CEP 29500-000, Guararema, Porto Alegre, ES, Brazil.
J Food Sci. 2020 Mar;85(3):816-823. doi: 10.1111/1750-3841.15064. Epub 2020 Feb 22.
The objective of this study was to evaluate the interaction of pro-vitamin A-rich sweet potato on iron bioavailability of biofortified cowpeas, using in vitro Caco-2 cells and in vivo depletion-repletion rat model. Mixtures of conventional rice with cultivars of iron-biofortified (Aracê, Xiquexique, and Tumucumaque) or conventional (Guariba) cowpeas with or without sweet potato biofortified with pro-vitamin A carotenoids were evaluated. The ratio of ferritin/total protein in Caco-2 cells was used as the index of cellular Fe uptake in the in vitro assay. The animal study evaluated the hemoglobin gain, the relative biological value, and the gene expression of transferrin and ferritin proteins by reverse transcription polymerase chain reaction. In the in vitro study, Xiquexique cowpea presented higher bioavailability of iron in the absence of sweet potato, and no difference was observed between the other cultivars of cowpea with and without sweet potato. The in vivo bioavailability (relative biological value of hemoglobin regeneration efficiency) differed statistically only between Guariba groups added to sweet potato and Tumucumaque. Ferritin mRNA expression did not differ between the test and control (ferrous sulfate) groups. Regarding the transferrin mRNA expression, there was a difference between the test and control groups except for the Xiquexique group. The association of rice and beans with sweet potato rich in carotenoids favored the gene expression of proteins involved in the iron metabolism, as well as its bioavailability, corroborating beneficial effects of this mixture. Xiquexique cowpea was shown to be the most promising compared to the other cultivars, exhibiting higher iron content in the digestible fraction, better in vitro bioavailability of iron, and transferrin gene expression. PRACTICAL APPLICATION: Data from the study indicated greater in vitro bioavailability of iron for Xiquexique cowpea and sweet potato mixtures, in addition to the greater regeneration efficiency of hemoglobin in vivo as the bioavailability of iron among biofortified beans, highlighting the promising benefits of biofortification.
本研究旨在评估富含维生素原 A 的甘薯对生物强化豇豆铁生物利用度的相互作用，使用体外 Caco-2 细胞和体内耗尽-补充大鼠模型。评估了常规大米与铁生物强化（Aracê、Xiquexique 和 Tumucumaque）或常规（Guariba）豇豆品种的混合物，以及添加或不添加富含维生素原 A 类胡萝卜素的甘薯。体外试验中，Caco-2 细胞中铁蛋白/总蛋白的比值被用作细胞铁摄取的指标。动物研究评估了血红蛋白的增加、相对生物学值以及通过反转录聚合酶链反应的转铁蛋白和铁蛋白基因的表达。在体外研究中，在没有甘薯的情况下，Xiquexique 豇豆的铁生物利用度更高，而其他豇豆品种与甘薯一起或不与甘薯一起使用时，铁生物利用度没有差异。体内生物利用度（血红蛋白再生效率的相对生物学值）仅在添加甘薯的 Guariba 组和 Tumucumaque 组之间存在统计学差异。铁蛋白 mRNA 表达在试验组和对照组（硫酸亚铁）之间没有差异。关于转铁蛋白 mRNA 表达，除了 Xiquexique 组外，试验组和对照组之间存在差异。富含类胡萝卜素的甘薯与大米和豆类的组合有利于铁代谢相关蛋白的基因表达及其生物利用度，证实了这种混合物的有益效果。与其他品种相比，Xiquexique 豇豆表现出更高的铁含量、更好的体外铁生物利用度和转铁蛋白基因表达，显示出更有前途的效果。
研究数据表明，与其他品种相比，Xiquexique 豇豆和甘薯混合物的铁体外生物利用度更高，生物强化豆的铁体内血红蛋白再生效率也更高，突出了生物强化的有前景的益处。
