基于有机元素分析的粉状食品中蛋白质含量的测定

Determination of protein content in powder food based on organic elemental analysis

目的建立基于有机元素分析的粉状食品中蛋白质含量的测定方法。方法采用VarioEL Ⅲ型元素分析仪对16种粉状食品中蛋白质含量进行测定,并与传统经典蛋白质测定方法——凯氏定氮法进行比较。结果元素分析法可准确测定样品中蛋白质含量,方法重复性和准确度均很好,与凯氏定氮法相比,测定结果相近,并且具有相当的测量精度,且有操作简单、无需复杂样品前处理、无溶剂和污染、样品需求量少、分析速度快、自动化程度高等优点。结论元素分析法可作为凯氏定氮法的替代和补充方法,用于粉状食品中蛋白质含量的测定。

Objective To establish a method for determination of protein content in food based on elemental analysis. Methods Protein contents of 16 kinds of powder food were determined by both elemental analysis and Kjeldahl’s method. Results based on two different methods were compared. Results The elemental analysis method could determine the protein content correctly, with good repeatability and accuracy, achieving comparable results to Kjeldahl’s method. The elemental analysis method showed more advantages such as little need of sample amount, simple experimental operation, high detecting efficiency and automaticity. Conclusion The elemental analysis method can be used to replace Kjeldahl’ s method for the determination of protein content in powder food.