Morris E R, Ellis R
J Nutr. 1980 Oct;110(10):2000-10. doi: 10.1093/jn/110.10.2000.
Low-phytate wheat bran was produced by enzymatic hydrolysis and extraction. Rat bioassay methods were utilized to determine bioavailability of iron and zinc in the low-phytate brans and to study the effect of dietary phytate/zinc molar ratio on zinc bioavailability when the phytate source was bran. Endogenous phytase activity hydrolyzed 80-100% of the phytate when wheat bran was incubated in water overnight. The relative biological values of the iron in raw bran and phytate-free bran were 98 and 113, respectively, compared to 100 for ferrous ammonium sulfate in a hemoglobin repletion assay. Low-phytate brans with phytate/zinc molar ratios of 8 or less were equivalent to zinc sulfate as dietary sources of zinc for growth of rats. Rats fed diets that contained wheat bran with zinc sulfate added to reduce the dietary phytate/zinc molar ratio from 40 or 50 to 20 grew at the same rate as rats fed a phytate-free diet, but femur zinc values were lower than those in the reference group. Gel filtration chromatography of extracts of raw and low-phytate brans suggested that zinc might be associated with phytate in wheat bran.
低植酸麦麸通过酶水解和提取制备而成。采用大鼠生物测定方法来测定低植酸麦麸中铁和锌的生物有效性，并研究当植酸来源为麦麸时，日粮中植酸/锌摩尔比对锌生物有效性的影响。当麦麸在水中过夜孵育时，内源性植酸酶活性可水解80% - 100%的植酸。在血红蛋白补充试验中，与硫酸亚铁的相对生物学效价为100相比，生麦麸和无植酸麦麸中铁的相对生物学效价分别为98和113。植酸/锌摩尔比为8或更低的低植酸麦麸作为大鼠生长的日粮锌源与硫酸锌相当。给大鼠喂食添加了硫酸锌以将日粮植酸/锌摩尔比从40或50降低到20的含麦麸日粮，其生长速度与喂食无植酸日粮的大鼠相同，但股骨锌含量低于参考组。对生麦麸和低植酸麦麸提取物进行凝胶过滤色谱分析表明，锌可能与麦麸中的植酸有关。
