LC-MS combines high separation ability of liquid chromatography with strong mass spectrometric structure identification. The advantages of LC-MS include high sensitivity and selectivity, minimal sample throughput, fast analysis speed and extensive structural information. It has been widely used in many fields, such as natural product analysis, pharmaceutical and food analysis, and environmental analysis.
In recent years, a great deal of researches have been conducted on the qualitative and quantitative aspects of food proteins and peptides. A variety of qualitative analyses of food proteins and peptides have been performed by LC-MS, such as accurate analysis of relative molecular weight, primary structural sequence, disulfide bond position, post-translational modifications (PTMs), etc. The quantitative analysis of proteins and peptides by LC-MS has been mainly achieved by two methods, i.e., label-free methods (peak intensities approach and spectral counting approach) and labeled methods (chemical labeling, metabolic labeling and enzymatic labeling methods). This chapter focuses on the application of qualitative and quantitative analysis of proteins and peptides in food sources.
