Comprehensive Profiling of Free Proteinogenic and Non-Proteinogenic Amino Acids in Common Legumes Using LC-QToF:...

Area of Science:

• Food Science
• Analytical Chemistry
• Biochemistry

Background:

• Legumes are a dietary staple, with increasing consumer demand for plant-based proteins.
• Pretreatments are used to reduce health risks associated with non-proteinogenic amino acids (NPAAs) in legumes.
• The tara flour incident highlights the need for better analytical methods for legume safety.

Purpose of the Study:

• To comprehensively map the distribution of free NPAAs and proteinogenic amino acids (PAAs) in various legume samples.
• To establish robust analytical methods for NPAA detection in legumes.
• To ensure the safety and quality of traditional and novel plant-based protein sources.

Main Methods:

• Liquid chromatography-mass spectrometry (LC-QToF) with MS/MS analysis was employed.
• Gel electrophoresis and soluble protein quantification were used for holistic protein analysis.
• An orthogonal approach combining multiple analytical techniques was utilized.

Main Results:

• A total of 47 NPAAs and 20 PAAs were identified across legume samples.
• Each sample contained at least 7-14 different NPAAs.
• Specific sulfur-containing NPAAs were predominantly found in *Phaseolus* and *Vigna* species.

Conclusions:

• The developed LC-MS method provides sensitive and specific NPAA detection.
• This approach enhances the quality control of plant-based proteins.
• The findings can aid in investigating foodborne illnesses linked to legume products.