人乳中唾液酸含量丰富，它对婴儿成长发育起到重要作用。然而，国内对于婴儿配方奶粉中唾液酸添加的工艺研究几乎没有开展。为了使婴儿配方奶粉中的唾液酸含量更接近人乳，本研究采用干法和湿法两种加工工艺将游离唾液酸添加到婴儿配方奶粉中，确定了两种加工工艺的婴儿配方奶粉中游离唾液酸的添加量范围，并且根据人乳中唾液酸存在模式，选择了最佳添加量。结果表明：干法生产每吨婴儿配方奶粉添加1.4~2.8 kg游离唾液酸，婴儿配方奶粉中的唾液酸含量为348~559 mg/L；湿法生产时游离唾液酸的添加量为400~800 mg/L，婴儿配方奶粉中唾液酸的含量为343~557 mg/L。尽管两种工艺均能满足婴儿配方奶粉中唾液酸含量标准，但干法工艺相比湿法工艺游离唾液酸的损耗小，节约经济成本。研究发现，随着游离唾液酸添加量逐渐增大，蛋白质结合唾液酸比例逐渐降低。当干法生产添加量为2.8 kg/t,湿法生产添加量为800 mg/L时，唾液酸在婴儿配方奶粉中的存在模式与人乳接近。

Sialic acid is rich in human milk, and it plays an important role in infants’ growth and development. However, the study on the adding of sialic acid to infant formula was less reported. In order to make sialic acid content in infant formula closer to breast milk, sialic acid adding to infant formula by dry and wet process and the adding dosage of sialic acid in infant formula were determined. The results showed that one ton of infant formula made by dry process should be added from 1400 to 2800 g free sialic acid, and the content of sialic acid in infant formulas were 348~559 mg/L. Adding dose of free sialic acid in infant formula milk powder by wet method was 400~800 mg/L, and the content of sialic acid in infant formulas were 343~557 mg/L. Although the two technologies could meet the content of sialic acid in infant formula standards, but dry process was more economic. The present study also suggested that the proportion of glycoprotein-bound-sialic acid was decreased with the increasing of adding doses of free sialic acid. When adding dose by dry process was 2.8 kg/t and 800 mg/L by wet peocess, the sialic acids in infant formula was close to the existing pattern of sialic acids in human milk.

“十二五”国家科技支撑计划课题(2011BAD09B0304)；食品安全与营养协同创新中心