Degradation of N-Acetyl-D-glucosamine and D-Glucosamine in Subcritical Water and Properties of the Degradation Products
2011
Wang, Rongchun | Kobayashi, Takashi | Adachi, Shuji
The degradation processes of N-acetyl-D-glucosamine (GlcNAc) and D-glucosamine in subcritical water were measured using a continuous tubular reactor at 170 to 210°C, and at 190 to 230°C, respectively. The degradation processes obeyed first-order kinetics in the tested temperature ranges. The temperature dependences of the degradation rate constants could be expressed by the Arrhenius equation, and the activation energies and the pre-exponential factors for GlcNAc and glucosamine were estimated to be 126 kJ/mol and 2.83 × 10(12) s-1, and 130 kJ/mol and 2.11 × 10(12) s-1, respectively. The pH values of the reaction mixtures, which were measured at room temperature, decreased for both substrates during degradation. The main degradation product of glucosamine was determined to be 5-(hydroxymethyl)-furfural. The degradation product of glucosamine possessed weak radical-scavenging ability, while that of GlcNAc did not.
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