Michaelsen K F, Pedersen S B, Skafte L, Jaeger P, Peitersen B
Department of Pediatrics, Hvidovre Hospital, University of Copenhagen, Denmark.
J Pediatr Gastroenterol Nutr. 1988 Mar-Apr;7(2):229-35. doi: 10.1097/00005176-198803000-00013.
Infrared (IR) analysis is widely used for routine analysis of cow milk in dairies. The aim of this study was to evaluate the precision and accuracy of an IR analyzer (Milko-scan 104) for measuring protein, fat, carbohydrate, and, indirectly, the energy content of human milk. The results of the IR analysis were compared with those of the following reference methods: protein--Kjeldahl (nitrogen minus nonprotein nitrogen); fat--Roese Gottlieb; carbohydrate--lactose enzymatic assay; energy--bomb calorimetry. The precision (repeatability coefficient of variation) of the IR results was high for all four components: protein 0.4%, fat 1.0%, carbohydrate 0.2%, and energy 0.1%. There was a close linear covariation between IR results and reference results. [Protein content was determined with an error (SD) of 0.01 g/100 ml and fat with an error of 0.03 g/100 ml.] The covariation between IR carbohydrate results and the results of the lactose assay was poor, probably because the oligosaccharides in the milk were included in the results from the IR analysis and not in the results from the lactose assay. IR analysis is a valuable method in research, especially in epidemiological surveys, in which large numbers of samples are analyzed, and for continuous monitoring of the nutritional value of human milk in milk banking programs.
红外（IR）分析在乳制品厂中广泛用于牛奶的常规分析。本研究的目的是评估一台红外分析仪（Milko-scan 104）测量人乳中蛋白质、脂肪、碳水化合物以及间接测量能量含量的精密度和准确性。将红外分析的结果与以下参考方法的结果进行比较：蛋白质——凯氏定氮法（总氮减去非蛋白氮）；脂肪——罗兹-哥特里法；碳水化合物——乳糖酶法测定；能量——弹式量热法。红外分析结果对所有四种成分的精密度（重复性变异系数）都很高：蛋白质0.4%，脂肪1.0%，碳水化合物0.2%，能量0.1%。红外分析结果与参考结果之间存在密切的线性协变关系。[蛋白质含量测定的误差（标准差）为0.01 g/100 ml，脂肪为0.03 g/100 ml。]红外分析得到的碳水化合物结果与乳糖测定结果之间的协变关系较差，可能是因为牛奶中的低聚糖包含在红外分析结果中，而不包含在乳糖测定结果中。红外分析在研究中是一种有价值的方法，特别是在需要分析大量样本的流行病学调查中，以及在母乳库计划中对人乳营养价值进行持续监测时。
