Fusch Gerhard, Rochow Niels, Choi Arum, Fusch Stephanie, Poeschl Susanna, Ubah Adelaide Obianuju, Lee Sau-Young, Raja Preeya, Fusch Christoph
Division of Neonatology, Department of Pediatrics, McMaster University, Hamilton, ON, Canada.
Division of Neonatology, Department of Pediatrics, McMaster University, Hamilton, ON, Canada.
Clin Nutr. 2015 Jun;34(3):465-76. doi: 10.1016/j.clnu.2014.05.005. Epub 2014 May 17.
BACKGROUND & AIMS: Significant biological variation in macronutrient content of breast milk is an important barrier that needs to be overcome to meet nutritional needs of preterm infants. To analyze macronutrient content, commercial infrared milk analyzers have been proposed as efficient and practical tools in terms of efficiency and practicality. Since milk analyzers were originally developed for the dairy industry, they must be validated using a significant number of human milk samples that represent the broad range of variation in macronutrient content in preterm and term milk. Aim of this study was to validate two milk analyzers for breast milk analysis with reference methods and to determine an effective sample pretreatment. Current evidence for the influence of (i) aliquoting, (ii) storage time and (iii) temperature, and (iv) vessel wall adsorption on stability and availability of macronutrients in frozen breast milk is reviewed.
Breast milk samples (n = 1188) were collected from 63 mothers of preterm and term infants. Milk analyzers: (A) Near-infrared milk analyzer (Unity SpectraStar, USA) and (B) Mid-infrared milk analyzer (Miris, Sweden) were compared to reference methods, e.g. ether extraction, elemental analysis, and UPLC-MS/MS for fat, protein, and lactose, respectively.
For fat analysis, (A) measured precisely but not accurately (y = 0.55x + 1.25, r(2) = 0.85), whereas (B) measured precisely and accurately (y = 0.93x + 0.18, r(2) = 0.86). For protein analysis, (A) was precise but not accurate (y = 0.55x + 0.54, r(2) = 0.67) while (B) was both precise and accurate (y = 0.78x + 0.05, r(2) = 0.73). For lactose analysis, both devices (A) and (B) showed two distinct concentration levels and measured therefore neither accurately nor precisely (y = 0.02x + 5.69, r(2) = 0.01 and y = -0.09x + 6.62, r(2) = 0.02 respectively). Macronutrient levels were unchanged in two independent samples of stored breast milk (-20 °C measured with IR; -80 °C measured with wet chemistry) over a period of 14 months.
Milk analyzers in the current configuration have the potential to be introduced in clinical routine to measure fat and protein content, but will need major adjustments.
母乳中宏量营养素含量存在显著的生物学差异，这是满足早产儿营养需求需要克服的一个重要障碍。为了分析宏量营养素含量，商业红外乳汁分析仪已被视为在效率和实用性方面高效且实用的工具。由于乳汁分析仪最初是为乳制品行业开发的，因此必须使用大量能代表早产和足月母乳中宏量营养素含量广泛变化的母乳样本进行验证。本研究的目的是用参考方法验证两款用于母乳分析的乳汁分析仪，并确定有效的样本预处理方法。本文综述了当前关于（i）分装、（ii）储存时间和（iii）温度以及（iv）容器壁吸附对冷冻母乳中宏量营养素稳定性和可利用性影响的证据。
从63名早产和足月婴儿的母亲处收集了1188份母乳样本。将两款乳汁分析仪：（A）近红外乳汁分析仪（美国Unity SpectraStar）和（B）中红外乳汁分析仪（瑞典Miris）与参考方法进行比较，例如分别用乙醚萃取、元素分析和超高效液相色谱 - 串联质谱法分析脂肪、蛋白质和乳糖。
对于脂肪分析，（A）测量精确但不准确（y = 0.55x + 1.25，r² = 0.85），而（B）测量既精确又准确（y = 0.93x + 0.18，r² = 0.86）。对于蛋白质分析，（A）精确但不准确（y = 0.55x + 0.54，r² = 0.67），而（B）既精确又准确（y = 0.78x + 0.05，r² = 0.73）。对于乳糖分析，两款仪器（A）和（B）均显示出两个不同的浓度水平，因此测量既不准确也不精确（分别为y = 0.02x + 5.69，r² = 0.01和y = -0.09x + 6.62，r² = 0.02）。在14个月的时间里，两份独立储存的母乳样本（-20°C用红外测量；-80°C用湿化学法测量）中的宏量营养素水平未发生变化。
当前配置的乳汁分析仪有潜力引入临床常规以测量脂肪和蛋白质含量，但需要进行重大调整。
