Abstract:

In this study, we investigated the synthesis of corn cyclo (His-Pro) (CHP) in aqueous solution by a high
temperature/pressure method from corn protein hydrolysate prepared in our laboratory. First of all, the one-factor-at-a-time
method was used to investigate the influences of reaction temperature, substrate concentration, KHCO3 concentration and
reaction time on CHP yield. Subsequently, the reaction conditions were optimized using response surface methodology.
Results revealed that the optimum reaction conditions were determined as follows: reaction temperature, 125.9 ℃;
reaction pressure, 0.25 MPa; substrate concentration, 20.5 mg/mL; KHCO3 concentration, 0.16 mol/L; and reaction time,
5.3 h, resulting in the maximum yield of CHP as high as 6.58 mg/g. The prepared CHP exhibited the expected structure as
confirmed by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).