Atomic Force microscopy techniques to investigate activated food packaging materials

Background: Since its invention, Atomic Force Microscopy has demonstrated to be one of the most interesting and useful techniques in many fields such as biology, optics and electronics to investigate nanoscale phenomena. Not only can it provide high resolution three-dimensional imaging of surfaces, but it also allows quantitative characterization of topographies, forces, mechanical and viscoelastic properties of interfaces at nanometer level. Scope and approach: Here we review current literature in the food packaging field where AFM has been proposed for the quantitative characterization of surfaces with functional layers allowing for exploitation of preservative properties as a result for example of higher permeability or antimicrobial activity. In fact, probing microscopes allow analysis of physical or mechanical properties of interfaces providing relevant information at the nanoscale with regard to different parameters such as dimensions, shapes, evolution and adhesion. Furthermore, recent developments in AFM have shown how fast imaging techniques can be implemented to allow time evolution description even at relatively high temperatures. What we aim is to establish how AFM is effectively promising in the research and development of innovative food packaging. Key findings and conclusions: AFM is largely used to characterize (bio)plastic materials for food packaging but also the comprehension of materials modification due to their activation is approached by using AFM, frequently combined to others instrumental analysis. In particular, even though AFM is basically used for topographical analysis of activated plastic materials, new and advanced AFM analysis are carried out for the characterization of different chemical and physical properties.