“…The peak located at 214.4 ppm was attributed to a C=O bond of ketones [28], which formed during the dehydration of sucrose [29]. The chemical shifts located at 180.3, 164.0, 127.0, 111.0, 153.6, and 54.9 ppm were assigned to the C6, C5, C4, C3, C2, and C1 of 5-HMF [30][31][32], respectively, and this result has also been clarified by HPLC in previous research [26,27]. The peaks from 154.4 to 158.1 ppm and 140.87 to 143.8 ppm were attributed to C2-C5 of 2,6-deoxyfructosazine (2,6-DOF) and 2,5-deoxyfructosazine(2,5-DOF), respectively [33,34].…”