Acidic Hydrothermal Dehydration of d‑Glucose into Humins: Identification and Characterization of Intermediates

The acidic hydrothermal dehydration of d-glucose into humins was studied. In addition to the well-known intermediates such as 5-hydroxymethylfurfural, which have been identified during the decomposition of d-glucose into humins, water-soluble oligomers of d-glucose (WSO) were identified. After isolation and characterization, the role of the WSO in the formation of humins was investigated. On this basis, we were able to propose a slight modification of the commonly admitted humins structure.