Effects of NMR transition point temperature on Maillard reaction rate in model food storage systems

Abstract

Functional nuclear magnetic resonance(NMR) was used to study the effect of NMR state diagram and transition point temperature(Tp) on Maillard reaction rate in model food systems.All systems had the same concentration of reactants,lysine and glucose,but different moisture and inert components,trehalose and sucrose.Carr-Purcell-Meiboom-Gill(CPMG) sequence was used to acquire the sample’s NMR relaxation data at different temperatures.High performance liquid chromatography(HPLC) was used to detect the consumption of reactants in the model food systems during stored in different temperatures.A trend of Tp temperatures change in the NMR state diagram was observed in the model matrixes with different moistures and sugar contents.A relative higher Tp temperature was observed in the low moisture sugar matrix and a relative slow reaction velocity in the identical matrix during storage at the same time.There were obvious reaction velocity differences on the temperatures above and below the Tp temperatures during storage at different temperatures.Different reaction velocities were observed in the samples having different sugar contents with same moisture during storage under an identical temperature.It was concluded that NMR state diagram and Tp temperature is available in accessing the better storage temperature,and an ingredient design would be helpful for the extension of shelf-life by decreasing the relative chemical reaction velocity during storage.