Nestlé Research Center, Vers-chez-les-blanc, CH-1000 Lausanne 24, Switzerland.
Food Chem. 2018 May 30;249:91-97. doi: 10.1016/j.foodchem.2017.12.061. Epub 2017 Dec 16.
In the present study an optimization of trienzyme treatment combining α-amylase, protease and γ-carboxy peptidase allowing complete sample preparation within a working day for the analysis of vitamin B9 (folate) in infant formula and adult/pediatric nutritional products is presented. The optimized sample preparation was applied to a set of samples representing most of the products in the marketplace. Results on Standard Reference Material 1849a were well in agreement with certified values. The main contributor to total folate was folic acid, 5-methyl-tetrahydrofolate was the only minor contributor in milk-based products. Soy-based formulas contained polyglutamates of 5-formyl-tetrahydrofolate. The relative contribution of polyglutamates to the total folate content remained low in the types of product included in this study. The results suggest that a simple di-enzyme treatment could be enough for these products, nevertheless, this should be carefully evaluated prior to making a decision on the use of tri- or di-enzyme treatment.
本研究对三酶处理（α-淀粉酶、蛋白酶和γ-羧基肽酶）进行了优化，可在一个工作日内完成婴儿配方奶粉和成人/儿科营养产品中维生素 B9（叶酸）的分析，实现完全的样品制备。优化后的样品制备方法应用于一组代表市场上大部分产品的样品。标准参考物质 1849a 的结果与认证值吻合良好。总叶酸的主要贡献者是叶酸，5-甲基四氢叶酸是基于乳的产品中的唯一次要贡献者。基于大豆的配方含有 5-甲酰基四氢叶酸的多谷氨酸盐。在本研究中包含的产品类型中，多谷氨酸盐对总叶酸含量的相对贡献仍然较低。结果表明，对于这些产品，简单的双酶处理可能就足够了，但在决定使用三酶或双酶处理之前，应仔细评估。
