Preparation and characterization of edible coating and film composed of sodium alginate/ylang-ylang oil/cellulose nanocrystals Pickering emulsion and its application to post-harvest control of mandarin (Citrus reticulata)

Pickering emulsion, a novel technique that uses solid particles as emulsion stabilizers has attracted attention because of its long-term storage stability and good coalescence stability. This can help to prolong the shelf life of fresh produce. The poor water vapor barrier, ultraviolet (UV), mechanical, and antifungal capacities of alginate film limit its application in fruit preservation. In this study, alginate (Alg) films with improved water vapor permeability (WVP), mechanical properties, and ultraviolet (UV) barrier were prepared with ylang-ylang oil (YYO) Pickering emulsion (PE). YYO was added as an antimicrobial agent. Cellulose nanocrystals (CNCs) were used as natural stabilizers to prepare YYO PE. The final coating comprised 1% Alg (alginate), Alg/0.24% CNCs, and Alg/0.5% YYO PE. The impacts of YYO-PE on the properties of Alg films were investigated, and their effects on post-harvest control of mandarins were evaluated. Gas chromatography-mass spectrometry (GCMS) was used to identify the components of YYO. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) showed an increase in the roughness of the films containing the Alg/YYO PE. Fourier transform infrared spectroscopy (FTIR) analysis revealed no new interactions in the Alg/YYO PE films. Moisture content (MC) and thermal properties were lower for Alg/YYO-PE films. The Alg/YYO-PE coating lowered the weight loss (7.84 ± 1.76%) and inhibited (p < 0.05) the growth of Penicillium italicum (P. italicum) and Penicillium digitatum (P. digitatum). The inhibition percentages were 56.02% and 47.98%, respectively, for the inoculated mandarins. In conclusion, the Alg/YYO PE coating and film have the potential to be an eco-friendly active packaging material in the food sector.