REQUIMTE/Departamento de Ciências Químicas, Laboratório de Bromatologia e Hidrologia, Faculdade de Farmácia, Universidade do Porto, Portugal.
REQUIMTE/Departamento de Ciências Químicas, Laboratório de Química Aplicada, Faculdade de Farmácia, Universidade do Porto, Portugal.
Food Chem. 2014;152:603-11. doi: 10.1016/j.foodchem.2013.12.023. Epub 2013 Dec 11.
Changes in macrominerals, trace elements and photosynthetic pigments were monitored at 5 stages of lettuce growth. Plants were grown in three experimental agriculture greenhouse fields (A1, A2 and A3). Soil composition was also monitored to understand its influence on lettuce composition. In general, the content of macrominerals, trace elements, chlorophylls and carotenoids decreased during lettuce growth and consequently, high nutritional value was observed at younger stages. A2 lettuces showed an increase of Fe, Al, Cr, V and Pb due to the different soil physicochemical parameters. Multiple linear regression analysis with stepwise variable selection, indicated that soil characteristics, namely, pH(CaCl2) for Fe and Cr, silt and fine-sand for Al and V, OM for Al and Pb, coarse-sand and CEC for Cr, had a key role determining element bioavailability and plant mineral content. Thus, lettuce nutritional value was strongly dependent of growth stage and soil characteristics.
在生菜生长的 5 个阶段监测了大量矿物质、微量元素和光合色素的变化。植物在三个实验性农业温室场（A1、A2 和 A3）中生长。还监测了土壤成分，以了解其对生菜成分的影响。一般来说，大量矿物质、微量元素、叶绿素和类胡萝卜素的含量在生菜生长过程中减少，因此在较年轻的阶段观察到高营养价值。由于不同的土壤物理化学参数，A2 生菜中 Fe、Al、Cr、V 和 Pb 的含量增加。逐步变量选择的多元线性回归分析表明，土壤特性，即 Fe 和 Cr 的 CaCl2 中的 pH 值、Al 和 V 的粉土和细砂、Al 和 Pb 的 OM、Cr 的粗砂和 CEC，对元素生物利用度和植物矿物质含量有重要作用。因此，生菜的营养价值强烈依赖于生长阶段和土壤特性。
