State Key Lab of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
International Joint Research Laboratory for Lipid Nutrition and Safety, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Nutrients. 2019 Aug 14;11(8):1892. doi: 10.3390/nu11081892.
Nervonic acid (24:1 n-9, NA) plays a crucial role in the development of white matter, and it occurs naturally in human milk. This study aims to quantify NA in human milk at different lactation stages and compare it with the NA measured in infant formulae. With this information, optimal nutritional interventions for infants, especially newborns, can be determined. In this study, an absolute detection method that uses experimentally derived standard curves and methyl tricosanoate as the internal standard was developed to quantitively analyze NA concentration. The method was applied to the analysis of 224 human milk samples, which were collected over a period of 3-30 days postpartum from eight healthy Chinese mothers. The results show that the NA concentration was highest in colostrum (0.76 ± 0.23 mg/g fat) and significantly decreased ( < 0.001) in mature milk (0.20 ± 0.03 mg/g fat). During the first 10 days of lactation, the change in NA concentration was the most pronounced, decreasing by about 65%. Next, the NA contents in 181 commercial infant formulae from the Chinese market were compared. The NA content in most formulae was <16% of that found in colostrum and less than that found in mature human milk ( < 0.05). No significant difference ( > 0.05) was observed among NA content in formulae with different fat sources. Special attention was given to the variety of n-9 fatty acids in human milk during lactation, and the results indicated that interindividual variation in NA content may be primarily due to endogenous factors, with less influence from the maternal diet.
神经酸（24:1n-9，NA）在白质的发育中起着至关重要的作用，并且它天然存在于母乳中。本研究旨在定量测定不同泌乳阶段母乳中的 NA，并与婴儿配方奶中的 NA 进行比较。有了这些信息，就可以为婴儿，特别是新生儿确定最佳的营养干预措施。在这项研究中，开发了一种绝对检测方法，该方法使用实验衍生的标准曲线和甲基二十三烷酸酯作为内标，以定量分析 NA 浓度。该方法应用于对 8 位健康中国母亲产后 3-30 天采集的 224 个母乳样本进行分析。结果表明，初乳中 NA 浓度最高（0.76±0.23mg/g 脂肪），成熟乳中（0.20±0.03mg/g 脂肪）显著降低（<0.001）。在哺乳期的前 10 天，NA 浓度的变化最为显著，下降了约 65%。随后，比较了来自中国市场的 181 种商业婴儿配方奶中的 NA 含量。大多数配方奶中的 NA 含量均低于初乳中的含量（<0.05），也低于成熟母乳中的含量（<0.05）。不同脂肪源配方奶中的 NA 含量无显著差异（>0.05）。特别关注了哺乳期母乳中 n-9 脂肪酸的多样性，结果表明，NA 含量的个体间差异可能主要是由内源性因素引起的，而受母体饮食的影响较小。
