Covalent and hydrophobic interactions play important roles in the formaldehyde scavenging ability of banana condensed tannins in aqueous solution

To characterize the interaction between banana condensed tannins (BCT) and formaldehyde as well as elucidate the involving mechanism, different techniques were utilized in the present study. Our results showed that BCT were a mixture of procyanidins and prodelphinidins with the degree of the polymerization of 2–9. With the increasing condensed tannin concentration (0.125–0.625 mg CE/mL), the formaldehyde scavenging ability of BCT (32.16–78.64 %) continuously enhanced. It was shown that formaldehyde could quench the fluorescence of BCT through a dynamic mechanism, while the binding of BCT and formaldehyde was a spontaneous process. According to the data of scavenging ability and spectroscopic analyse, the hydrophobic and covalent interactions between BCT and formaldehyde mainly contributed to the formaldehyde scavenging ability of BCT Moreover, the morphologies of BCT-formaldehyde complexes confirmed the interactions between BCT and formaldehyde as well. Therefore, BCT could be developed as promising formaldehyde scavengers during food production and processing in the future. •BCT were a mixture of procyanidin and prodelphinidin oligomers.•The formaldehyde scavenging ability of BCT increased with rising CT concentrations.•Formaldehyde could be eliminated by BCT via covalent and hydrophobic interactions.•Formaldehyde could quench the fluorescence of BCT through a dynamic mechanism.•BCT could be developed as promising formaldehyde scavengers during food production.