Abstract: The applicability of enzyme colorimetry as specified in the National Food Safety Standard: Determination of Choline in Infant Food and Milk Products (GB 5413.20－2013) for the determination of choline in infant formula for special medical purposes was evaluated using quality control and actual samples as well as spiked recovery and precision tests. The theoretical value of choline content in quality control samples was 171.5 mg/100 g, and the measured value was 168.4 mg/100 g. The measured result was within the allowable error range indicating its reliability. Spiked recoveries for infant formula and quality control samples were 96.1%–98.4% with relative standard deviation (RSD) of 1.43%, indicating high accuracy and precision of the method. When the method was applied to 24 batches of commercial samples, the measured values of choline content met the requirements of the national standard. Accordingly, enzyme colorimetry can be used to detect choline i n infant formula for special medical purposes.

Key words: enzyme colorimetry, infant formula for special medical purposes, choline

摘要： 通过质控样品测定、加标回收实验、精密度实验和实际样品测定，考察GB 5413.20—2013《食品安全国家标准 婴幼儿食品和乳品中胆碱的测定》中酶比色法测定特殊医学用途婴儿配方食品中胆碱的适用性。结果表明：质控样的胆碱含量理论值为171.5 mg/100 g，测定值为168.4 mg/100 g，测定结果在允许误差范围内，说明实验结果可靠；乳粉样品和质控样的加标回收率为96.1%～98.4%，相对标准偏差为1.43%，说明酶比色法准确度较高，精密度较好；24 批次市售特殊医学用途婴儿配方乳粉的胆碱含量均符合GB 5413.20—2013的要求，表明酶比色法可以用于检测特殊医学用途婴儿配方食品中的胆碱含量。

关键词: 酶比色法, 特殊医学用途婴儿配方食品, 胆碱