Tannic acid modulated the wall compactness of cinnamaldehyde-loaded microcapsules and enhanced inhibitory effect on Aspergillus brasiliensis

Summary The evaluation of antifungal properties in cinnamaldehyde (CA)-loaded microcapsules is significant to clarify potential food applications in various food matrices and systems. The impact of tannic acid (TA) crosslinking on the release and the antifungal properties of CA microcapsules was investigated based on gelatin/gum Acacia complex coacervates. The inhibition zone diameter of microencapsulated CA against Aspergillus brasiliensis was dependent on the TA addition and retained 26.1 ± 0.1 mm after 180-day storage at 25 °C. Specifically, TA enhanced hydrogen bond interactions between the microcapsule wall materials and favoured a sustained release of CA during the incubation with Aspergillus brasiliensis. Meanwhile, confocal laser scanning microscopic observation revealed that the microstructure of multinuclear microcapsules was more compact and intact under the crosslinking of 0.4% TA. The comparation of microscopic morphology and membrane potential of Aspergillus brasiliensis exerted a synergistic antifungal effect between CA and TA crosslinked microcapsules.