Applications of in-capillary reaction micellar electrokinetic chromatography in the food industry

This review describes the quantitative analysis of in-capillary reactions by using capillary electrophoresis (CE) in the food industry. An electrophoretic analysis of products of an enzyme reaction of a substrate by in-capillary reaction was useful for the activity measurement of glucoamylase in sake rice koji. p-Nitrophenyl-β-d-maltoside was employed as a substrate and p-nitrophenyl-β-d-glucopyranoside was the product of the enzyme reaction. The glucoamylase activity of sake rice koji samples gave a good linear relationship with the peak area observed in the in-capillary enzyme reaction method. Also, in-capillary micellar electrokinetic chromatography (MEKC) was used for analyzing the Monascus pigment-mediated degradation of mutagenic 3-hydroxyamino-1-methyl-5H-pyrido[4,3-b]indole. During the electrophoresis, the mutagen and the pigment, due to their different migration velocities, mix for a certain period of time to interact, and then they are separated and quantitated. The in-capillary reaction MEKC method can be applied to the routine quality control of enzyme activities in the food industry and the evaluation of mutagenic compounds in food materials.