Visualization of dipeptidyl peptidase B enzymatic reaction in rice koji using mass spectrometry imaging.

Enzyme histochemistry via mass spectrometry imaging (MSI) has garnered attention as a straightforward approach for visualizing enzymatic reactions. While several studies in the medical and physiological fields have shown its promising application potential, its applicability to agricultural or food studies has not yet been demonstrated. Rice koji, known as an enzyme source for various fermented products, is a suitable model for demonstrating the applicability of this method to food-related materials.