Edible γ-cyclodextrin metal–organic frameworks constructed for adsorbing saturated and unsaturated aldehydes to remove off-odors in surimi

The persistent off-odor in aquatic products has impeded the growth of aquatic industry. An innovative strategy was proposed to remove off-odors using edible γ-cyclodextrin metal–organic frameworks (γ-CD-MOFs). The interaction between the γ-CD-MOFs and off-odors of three aldehydes (nonanal, 4-heptenal, and 2,4-decadienal) is analyzed by adsorption kinetics, isotherms, thermodynamics, and density functional theory (DFT) calculations. The γ-CD-MOFs exhibited the highest adsorption rate for 2,4-decadienal (63.9 %), possibly due to electron delocalization caused by large π bond to enhance the reactivity of the molecule. The highest adsorption capacity of γ-CD-MOFs was observed at 40 °C, but the aldehydes underwent a self-aldol condensation reaction at 90 °C, significantly affecting the adsorption capacity. The aldehydes adsorption by γ-CD-MOFs could have occurred via hydrogen bonding and van der Waals interaction. Consequently, γ-CD-MOFs effectively reduce the levels of volatile aldehyde substances, removing off-odors generated by lipid oxidation in surimi. This work offers novel application for MOFs in the food industry.