The impact of infant formula production on the concentrations of 3-MCPD and glycidyl esters

Fatty acid esters of 3-monochloropropanediol (3-MCPD), 2-monochlorpropanediol (2-MCPD), and glycidol are process-induced chemical contaminants found in refined vegetable oils. Due to their toxicological properties, there is potential concern regarding exposure to these compounds, particularly for formula-fed infants where refined edible oils are the primary fat source in commercial infant formulas. In order to assess exposure, 55 commercial oil samples, specifically intended for use in infant formula, were collected in 2015 from various infant formula manufacturers in the United States and analysed using a LC-MS/MS direct detection method. At the time of collection, there were no validated methods for the analysis of MCPD and glycidyl esters in infant formula. Therefore, analysis of these commercial oil samples served as an alternative for confirming the presence of these ester contaminants in infant formula. Bound 3-MCPD and glycidol concentrations in these oils ranged from below the limit of quantitation (−1 and −1, respectively. Highest ester concentrations were observed in palm olein samples. Concentrations of bound 3-MCPD and glycidol in the commercial oils were consistent with previously published occurrence studies at the time, suggesting that oils used in the manufacture of infant formula were similar (or processed in a similar manner) as refined oils marketed directly to consumers in 2015. In order to determine if conditions during infant formula production impact the presence of 3-MCPD and glycidyl esters in the finished products, concentrations in oils were compared to concentrations in finished infant formula collected at approximately the same time. The comparison revealed that conditions used in the manufacture of infant formula likely initiate the destruction or conversion of glycidyl esters to other compounds, resulting in lower amounts of bound glycidol in the final product relative to the concentrations originally present in the refined oils.

3-氯丙二醇（3-monochloropropanediol, 3-MCPD）、2-氯丙二醇（2-monochlorpropanediol, 2-MCPD）以及缩水甘油的脂肪酸酯，是一类在精炼植物油中经加工诱导产生的化学污染物。鉴于其毒理学特性，人们对接触这类化合物存在潜在健康担忧，其中尤以配方喂养婴儿群体的风险最为突出——这类婴儿的商业婴儿配方食品中，精炼食用油是其主要脂肪来源。2015年，研究人员从美国多家婴儿配方食品制造商处采集了55份专用于婴儿配方食品生产的商用油脂样品，并采用液相色谱-串联质谱（LC-MS/MS）直接检测法开展分析。彼时，尚无针对婴儿配方食品中3-MCPD酯与缩水甘油酯的经验证分析方法，因此对这批商用油脂样品的分析可作为确认婴儿配方食品中存在这类酯类污染物的替代方案。上述油脂中结合态3-MCPD与缩水甘油的浓度均低于定量限（二者的定量限分别为-1和-1），其中棕榈油精样品中的酯类污染物浓度最高。这批商用油脂中的结合态3-MCPD与缩水甘油浓度，与2015年时已发表的相关污染水平研究结果一致，这表明用于婴儿配方食品生产的油脂，与同期直接面向消费者销售的精炼油脂具有相似性（或采用了相似的加工工艺）。为探究婴儿配方食品生产过程中的工艺条件是否会影响最终产品中3-MCPD酯与缩水甘油酯的残留水平，研究人员将油脂样品中的污染物浓度与同期采集的成品婴儿配方食品中的污染物浓度进行了对比。对比结果显示，婴儿配方食品生产环节采用的工艺条件，可能会促使缩水甘油酯发生降解或转化为其他化合物，最终使得成品中结合态缩水甘油的残留量低于原始精炼油脂中的初始浓度。