Abstract
The inhibition of Angiotensin I converting enzyme (ACE) by Maillard reaction products (MRP) prepared from sugars and amino acids were investigated.Sixteen kinds of amino acids and glucose/xylose were reacted to make MRPs.Among the MRPs prepared, those from His, Arg, Cys, Leu, Ile and Thr showed relatively strong ACE inhibitory activities.It was observed that MRPs from basic amino acids had both relatively strong ACE inhibitory activities and colors, however, there was no relationship between color development and ACE inhibitory activities.Further investigation was carried out using the MRP from His-Glc.ACE inhibitory substances were produced under a wide range of initial reaction pHs.In addition, it was observed that the ACE inhibitory activityof the MRP product depends more on the initial His concentration than on the initial Glc concentration.When the His-Glc MRPs were fractionated by Sephadex G-25 column chromatography, compounds with a wide range of molecular weights were observed to have ACE inhibitory activity.The inhibitory action of the His-Glc MRP was overcome by the addition of the Zn2+ ion, which is located at theactive site of ACE.In the His-Glc Maillard reaction, the production patterns of the ACE inhibitory substances during the reaction time differed from each other at different reaction pHs, although mostof the products had their ACE inhibitory activities reduced by the addition of Zn2+ ion.
