Nestlé Research, Vers-Chez-Les-Blanc, 1000 Lausanne, Switzerland.
Current address: GSK Consumer Healthcare S.A., Route de l'Etraz 2, 1260 Nyon, Switzerland.
Molecules. 2018 Oct 16;23(10):2650. doi: 10.3390/molecules23102650.
Human milk oligosaccharides (HMO) are the third most abundant solid component of human milk. It is likely that they are responsible for at least some of the benefits experienced by breast-fed infants. Until recently HMO were absent from infant formula, but 2'-fucosyllactose (2'-FL) and lacto-N-neoteraose (LNnT) have recently become available as ingredients. The development of formula containing these HMO and the quality control of such formula require suitable methods for the accurate determination of the HMO. We developed two different approaches for analysis of 2'-FL and LNnT in formula; high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) and hydrophilic interaction liquid chromatography with fluorescence detection (HILIC-FLD). In lab trials using blank formula spiked with the two oligosaccharides, both approaches worked well with recoveries of 94⁻111% (HPAEC-PAD) and 94⁻104% (HILIC-FLD) and RSD (iR) of 2.1⁻7.9% (HPAEC-PAD) and 2.0⁻7.4% (HILIC-FLD). However, when applied to products produced in a pilot plant, the HPAEC-PAD approach sometimes delivered results below those expected from the addition rate of the ingredients. We hypothesize that the oligosaccharides interact with the formula matrix during the production process and, during sample preparation for HPAEC-PAD those interactions have not been broken. The conditions required for labeling the HMO for detection by the FLD apparently disrupt those interactions, and result in improved recoveries. It is likely that both analytical approaches are appropriate if a suitable extraction process is used to recover the HMO.
人乳寡糖（HMO）是母乳中第三大固体成分。它们很可能是母乳喂养的婴儿获得某些益处的原因之一。直到最近，婴儿配方奶粉中还没有 HMO，但 2'-岩藻糖基乳糖（2'-FL）和乳-N-新四糖（LNnT）最近已成为可用的成分。含有这些 HMO 的配方的开发以及此类配方的质量控制都需要合适的方法来准确测定 HMO。我们开发了两种不同的方法来分析配方中的 2'-FL 和 LNnT；高效阴离子交换色谱-脉冲安培检测（HPAEC-PAD）和亲水相互作用液相色谱-荧光检测（HILIC-FLD）。在使用空白配方添加两种寡糖的实验室试验中，这两种方法的回收率均为 94⁻111%（HPAEC-PAD）和 94⁻104%（HILIC-FLD），相对标准偏差（iR）为 2.1⁻7.9%（HPAEC-PAD）和 2.0⁻7.4%（HILIC-FLD）。然而，当应用于在中试工厂生产的产品时，HPAEC-PAD 方法有时会给出低于预期的结果，这可能是由于成分的添加率造成的。我们假设寡糖在生产过程中与配方基质相互作用，而在用于 HPAEC-PAD 的样品制备过程中，这些相互作用尚未被打破。FLD 检测所需的标记 HMO 的条件显然会破坏这些相互作用，从而导致回收率提高。如果使用合适的提取过程来回收 HMO，那么这两种分析方法都可能是合适的。
