Evaluation of the antifungal properties of chitosan coating on cut apples using a non-invasive image analysis technique



Image analysis techniques have often been chosen as fundamental tools for evaluating the surface and/or structure of organic and inorganic materials over a broad range of scales. In the study reported, a simple image capture system comprising a commercial desktop scanner combined with free image analysis software was used to evaluate the efficiency of antifungal activity of commercial medium-molecular-weight chitosan as an edible coating on sliced apples. Fungal growth rate (predominantly Penicillium sp. and Alternaria sp.) was assessed via images acquired twice daily and binary-transformed for quantitative analysis. The inhibitory effect of chitosan coating on the mycelial fungi growth on cut apple surfaces was confirmed. Chitosan deposited on glass slides was used to simulate film formation and its structure was characterized using atomic force microscopy, revealing a thin porous formation. Copyright © 2011 Society of Chemical Industry