Yan Jingjing, Wang Min, Yang Mengrui, Zhou Jian, Xue Xiaofeng, Wang Tongtong
Key Laboratory of Agro-Product Quality and Safety, Ministry of Agriculture and Rural Affairs, Institute of Quality Standard and Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences, 100081 Beijing, China.
Key Laboratory of Agro-Product Quality and Safety, Ministry of Agriculture and Rural Affairs, Institute of Quality Standard and Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences, 100081 Beijing, China.
Food Chem. 2022 Aug 15;385:132674. doi: 10.1016/j.foodchem.2022.132674. Epub 2022 Mar 9.
The accurate measurement of bovine lactoferrin (bLF) attracts wide attention in food and nutraceutical applications as its important physiological and nutritional functions. We present SI traceable procedures for assessing bLF purity using mass balance method and amino acid (AA)-based isotope dilution mass spectrometry (IDMS). The mass balance method was revealed with a purity of 0.938 ± 0.011 g/g by deducting all aspects of impurities, including related structure impurities of 4.60%, ignition residue of 0.28%, Cl of 1.10%, SO of 0.13%, and moisture of 0.17%. The AA-based IDMS quantitative result was 0.937 ± 0.027 g/g. Hydrolysis conditions were optimized and methodology validation including, accuracy, precision, were studied. Good consistency was achieved between the two independent strategies and bLF purity assigned via the weighted mean value of their results was 0.938 ± 0.015 g/g. These analyses are expected to be applicable to proteins quantification and development of LF certified reference materials.
由于牛乳铁蛋白（bLF）具有重要的生理和营养功能，其准确测量在食品和营养保健品应用中备受关注。我们提出了使用质量平衡法和基于氨基酸（AA）的同位素稀释质谱法（IDMS）来评估bLF纯度的国际单位制（SI）可溯源程序。通过扣除所有杂质方面，包括4.60%的相关结构杂质、0.28%的灼烧残渣、1.10%的氯、0.13%的硫和0.17%的水分，质量平衡法得出的纯度为0.938±0.011 g/g。基于AA的IDMS定量结果为0.937±0.027 g/g。优化了水解条件，并研究了包括准确度、精密度在内的方法验证。两种独立策略之间实现了良好的一致性，通过其结果的加权平均值确定的bLF纯度为0.938±0.015 g/g。这些分析有望应用于蛋白质定量和乳铁蛋白标准物质的研制。
