Optimizing food waste hydrothermal parameters to reduce Maillard reaction and increase volatile fatty acid production

The occurrence of the Maillard reaction and melanoidins formation during the hydrothermal treatment of food waste can reduce the yield of volatile fatty acids (VFA); however, few studies have investigated the adverse effects of the Maillard reaction. This study identified the impact of hydrothermal treatment parameters on hydrolysis and melanoidins formation and optimized the hydrothermal treatment conditions to enhance VFA production by minimizing the impact of the Maillard reaction. A response surface methodology was employed to optimize the hydrothermal treatment parameters and VFA production was evaluated. Results showed that temperature, reaction time, and pH were significant interacting factors with respect to hydrolysis and melanoidins formation while the C/N ratio and moisture content of food waste had little impact. The optimal conditions for hydrothermal treatment (temperature of 132 °C, reaction time of 27 min, and a pH of 5.6) enhanced VFA production by 22.1%. Under optimal hydrothermal treatment conditions, a higher initial C/N ratio further increased VFA production.