Zhou J R, Fordyce E J, Raboy V, Dickinson D B, Wong M S, Burns R A, Erdman J W
Division of Nutritional Sciences, University of Illinois, Urbana 61801.
J Nutr. 1992 Dec;122(12):2466-73. doi: 10.1093/jn/122.12.2466.
The inhibitory effect of phytic acid in soybean products on zinc bioavailability was evaluated in two experiments in rats. In Experiment 1, soybean flours containing different natural phytic acid levels produced by sand culture techniques that limited phosphorus during growth of the soybean plants were formulated into diets. The rats fed a higher phytic acid level diet had lower food intake, depressed weight gain, and lower tibia zinc gain (P < 0.05). A negative, linear relationship between tibia zinc gain and dietary phytic acid level was found. In Experiment 2, two commercially produced soybean isolates containing either normal phytic acid level or a reduced level were formulated into diets. Slope ratio analysis revealed that relative zinc bioavailability from phytic acid-containing soybean isolate-based diets was significantly reduced (P < 0.05) compared with control diets. Reduced phytic acid soybean isolate-containing diets resulted in a significant increase of zinc bioavailability compared with normal phytic acid diets (P < 0.01). These results coupled with other reports indicate that phytic acid is the primary inhibitory factor in soybean products that results in reduced zinc bioavailability and that phytate reduction in soybean protein increases zinc bioavailability.
在两项大鼠实验中评估了大豆制品中植酸对锌生物利用度的抑制作用。在实验1中，通过在大豆植株生长期间限制磷的砂培技术生产出含不同天然植酸水平的大豆粉，并将其配制成日粮。饲喂较高植酸水平日粮的大鼠食物摄入量较低、体重增加受抑制且胫骨锌增量较低（P<0.05）。发现胫骨锌增量与日粮植酸水平之间呈负线性关系。在实验2中，将两种市售的分别含有正常植酸水平或降低植酸水平的大豆分离蛋白配制成日粮。斜率比分析显示，与对照日粮相比，基于含植酸大豆分离蛋白的日粮中锌的相对生物利用度显著降低（P<0.05）。与正常植酸日粮相比，含降低植酸大豆分离蛋白的日粮使锌生物利用度显著增加（P<0.01）。这些结果与其他报告表明，植酸是大豆制品中导致锌生物利用度降低的主要抑制因素，且大豆蛋白中植酸盐的减少会增加锌生物利用度。
