Mitigation of off-flavors in foods by cyclodextrins: Current status and future perspectives

Off-flavors are widely prevalent in various food products, significantly diminishing their sensory appeal and overall quality. Cyclodextrins (CDs), which are tasteless and odorless, have garnered widespread attention due to their remarkable ability to mitigate off-flavors. They have been applied in plant-based products, dairy products, fruit juice, alcoholic beverages, and fish etc. In the present review, the volatile and non-volatile off-flavor compounds in foods were summarized first, and the mitigation mechanism of off-flavors by CDs were reviewed further. Additionally, various characterization methods were compared to investigate the mechanisms underlying the mitigation of off-flavors, including scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, and molecular simulation etc. It is concluded that the primary mechanism by which CDs mitigate off-flavors involve the molecular encapsulation of odorants and precursors that cause off-flavors. Besides, the synergistic effect of cyclodextrins and other compounds further contribute to odor mitigation in foods, which should be paid more attention. β-cyclodextrin (β-CD) is generally applicable to five food systems, α-cyclodextrin (α-CD) and γ-cyclodextrin (γ-CD) may be more appropriate for smaller and larger molecules, respectively. In the end, the authors concluded that a combination of the experiment, molecular simulation and machine learning to investigate CD/off-flavor interactions should be emphasized in the future work.