Mendoza C, Viteri F E, Lönnerdal B, Young K A, Raboy V, Brown K H
Institute of Nutrition of Central America and Panama, Guatemala City, Guatemala.
Am J Clin Nutr. 1998 Nov;68(5):1123-7. doi: 10.1093/ajcn/68.5.1123.
Genetically modified, low-phytic acid strains of maize were developed to enhance mineral absorption, but have not been tested previously in humans.
We evaluated the mineral and phytic acid contents of a low-phytic acid "flint" maize (LPM, the lpa-1-1 mutant) and its parent, wild-type strain (WTM) and measured iron absorption from tortillas prepared with each type of maize and from a reference dose of ferrous ascorbate.
Proximate composition and mineral and phytic acid contents were measured by standard techniques. Iron absorption from tortillas was evaluated by using the extrinsic tag method and was measured as the incorporation of radiolabeled iron into the red blood cells of 14 nonanemic men 2 wk after intake.
The phytic acid content of LPM was 3.48 mg/g, approximately 35% of the phytic acid content of WTM; concentrations of macronutrients and most minerals were not significantly different between strains. Iron absorption results were adjusted to 40% absorption of ferrous ascorbate. Iron absorption was 49% greater from LPM (8.2% of intake) than from WTM (5.5% of intake) tortillas (P < 0.001, repeated-measures analysis of variance).
Consumption of genetically modified, low-phytic acid strains of maize may improve iron absorption in human populations that consume maize-based diets.
为提高矿物质吸收而培育出了转基因低植酸玉米品种，但此前尚未在人体中进行过测试。
我们评估了一种低植酸“硬质”玉米（LPM，lpa - 1 - 1突变体）及其亲本野生型菌株（WTM）的矿物质和植酸含量，并测量了用每种玉米制作的玉米饼以及参考剂量的抗坏血酸亚铁中的铁吸收情况。
采用标准技术测量近似成分、矿物质和植酸含量。通过使用外源性标记法评估玉米饼中的铁吸收情况，并在摄入后2周测量14名非贫血男性红细胞中放射性标记铁的掺入量。
LPM的植酸含量为3.48 mg/g，约为WTM植酸含量的35%；两种菌株之间的常量营养素和大多数矿物质浓度无显著差异。铁吸收结果调整为抗坏血酸亚铁吸收量的40%。LPM玉米饼的铁吸收量（摄入量的8.2%）比WTM玉米饼（摄入量的5.5%）高49%（P < 0.001，重复测量方差分析）。
食用转基因低植酸玉米品种可能会改善以玉米为主食的人群的铁吸收情况。
