Fransson G B, Lönnerdal B
J Pediatr. 1982 Oct;101(4):504-8. doi: 10.1016/s0022-3476(82)80690-2.
Human milk was fractionated and analyzed for the distribution of copper, zinc, calcium, and magnesium among various fractions. In whole milk the concentration of copper was 0.27 +/- 0.13 micrograms/ml, zinc 1.10 +/- 1.19 microgram/ml, calcium 241.2 +/- 61.9 microgram/ml, and magnesium 41.4 +/- 15.2 micrograms/. Most of the Cu, Zn, Ca, and Mg was found in the skim milk, but significant amounts of Cu, Zn, and Ca were found in the fat, most likely associated with the fat globule membrane. Less than 4% of each of the elements was found in the casein. A low molecular weight fraction contained 26% of total Cu. 25% of Zn, 34% of Ca, and 54% of MG. Gel filtration demonstrated Zn and Cu in skim milk binding to two different proteins with molecular weight (MW) greater than 400,000 and 60 to 80,000, as well as to LMW compounds. The unique distribution and binding of these elements in the milk may, in part, explain the known high bioavailability of trace elements and minerals in human milk.
对人乳进行了分级，并分析了铜、锌、钙和镁在不同级分中的分布情况。在全脂牛奶中，铜的浓度为0.27±0.13微克/毫升，锌为1.10±1.19微克/毫升，钙为241.2±61.9微克/毫升，镁为41.4±15.2微克/毫升。大部分的铜、锌、钙和镁存在于脱脂乳中，但在脂肪中也发现了大量的铜、锌和钙，很可能与脂肪球膜有关。在酪蛋白中发现的每种元素均不到4%。一种低分子量级分含有总铜的26%、锌的25%、钙的34%和镁的54%。凝胶过滤显示，脱脂乳中的锌和铜与两种不同的蛋白质结合，其分子量（MW）大于400,000和60至80,000，也与低分子量化合物结合。这些元素在牛奶中的独特分布和结合可能部分解释了人乳中已知的微量元素和矿物质的高生物利用度。
