Visualization of Functional Food Factors by Matrix-Assisted Laser Desorption/Ionization Imaging Mass Spectrometry.

Dietary habit is closely associated with healthspan. Functional food factors are key to maintaining a health metabolism in our bodies. Because functional food factors are main components to determine the quality of foods, many technologies have been established to analyze functional factors in foods. High-performance liquid chromatography-mass spectrometry or gas chromatography-mass spectrometry is a solid approach to detect functional food factors with high sensitivity and specificity. Findings obtained from these mass spectrometric approaches play essential roles in estimating the quality of foods. However, these technologies are not available for the analysis of the spatial distribution of molecules of interest in foods. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is considered an ideal approach to visualize distribution of molecules in foods. MALDI-MSI is a two-dimensional MALDI-MS technology that can detect compounds in a tissue section without purification, separation, or labeling. MALDI-MSI can be used to visualize the spatial distribution of wide range of food components including protein, peptides, amino acids, lipids, carbohydrate, and vitamins. Although the methodology of MALDI-MSI in food science is not yet fully established, the versatility of MALDI-MSI is expected to open a new frontier in food science. In this mini review, we briefly summarized the applications of MALDI-MSI in the field of food science.