Preparation and characterization of pectin-based edible coating agent encapsulating carvacrol/HPβCD inclusion complex for inhibiting fungi

In this study, the pectin-based edible coatings encapsulating carvacrol/2-hydroxypropyl-β-cyclodextrin inclusion complex (CAR/HPβCD-IC) were fabricated and their antifungal activities were investigated. The inclusion complex of CAR/HPβCD was demonstrated to be successfully synthesized by the characterization of UV–vis spectroscopy, fluorescence emission spectroscopy, FT-IR, 1H NMR, TGA and DSC. The fluorescence emission spectra analysis suggested that stoichiometric ratio of carvacrol and HPβCD for forming the inclusion complex was 1:1. The aqueous solubility and thermal stability of carvacrol were significantly enhanced after inserting into HPβCD cavity. Furthermore, the inclusion complex exhibited strong antifungal activities against pathogens of Botrytis cinerea and Alternaria alternata. On the other hand, an edible active coating was prepared by the addition of CAR/HPβCD-IC into pectin matrix. The steady rheology results of film-coatings indicated that the apparent viscosity of edible coatings was decreased with the addition of CAR/HPβCD-IC. In contrast, CAR/HPβCD-IC increased the thermal stability of pectin. In addition, the pectin/CAR/HPβCD-IC coating as an active packaging material suppressed the colony growth of B. cinerea and A. alternata in vitro. Results from the present study demonstrated that the pectin-based edible coating encapsulating CAR/HPβCD-IC was a promising coating material for food preservation.