Forsum E, Lönnerdal B
J Nutr. 1979 Feb;109(2):185-92. doi: 10.1093/jn/109.2.185.
The levels of individual proteins and other nitrogen containing substances differ considerably between cow's milk and human milk. Therefore, during manufacture of infant formulas, attempts are made to simulate the protein composition of human milk. However, the composition and nutritional characteristics of human milk protein are incompletely known. In this paper, the protein quality of breast milk protein with and without the non-protein-nitrogen (NPN) substances present in human milk was studied with growing rats and compared to two formulas, one "adapted" commercial infant formula and a suggested further modified, possibly improved, infant formula. Detailed examinations of protein and amino acid composition of the test diets are given. Breast milk protein with added NPN substances showed a lower protein quality than all other test proteins. Breast milk protein without NPN substances and the protein of the suggested infant formula were of similar quality while the protein of the commercial adapted formula was significantly better than all other test proteins. The use of rat growth assays in the evaluation of protein quality of infant formulas is discussed.
牛奶与人乳中各蛋白质及其他含氮物质的含量差异很大。因此，在婴儿配方奶粉的生产过程中，人们试图模拟人乳的蛋白质组成。然而，人乳蛋白质的组成和营养特性尚未完全明确。本文利用生长大鼠研究了含和不含人乳中非蛋白氮（NPN）物质的母乳蛋白质的质量，并与两种配方奶粉进行了比较，一种是“适应性”商业婴儿配方奶粉，另一种是建议进一步改良、可能有所改进的婴儿配方奶粉。文中给出了对试验日粮蛋白质和氨基酸组成的详细检测。添加了NPN物质的母乳蛋白质的质量低于所有其他试验蛋白质。不含NPN物质的母乳蛋白质和建议的婴儿配方奶粉的蛋白质质量相似，而商业适应性配方奶粉的蛋白质质量明显优于所有其他试验蛋白质。本文还讨论了使用大鼠生长试验评估婴儿配方奶粉蛋白质质量的问题。
