Super-Resolution Microscopy and Their Applications in Food Materials: Beyond the Resolution Limits of Fluorescence Microscopy

Super-resolution microscopy (SRM) techniques have revolutionized the process of obtaining images beyond Abbe's diffraction limit (similar to 200 nm) of the light microscopes. It is possible to obtain images in 2D and 3D by reaching a lateral resolution of up to 10 nm of the cellular ultrastructure and biomolecules labelled with fluorophores. However, SRM is relatively unknown and rarely applied in food science, yet it has huge potential for the development of food nanotechnology. There is a focus on structured illumination microscopy (SIM), stimulated emission depletion (STED) microscopy, photoactivated localization microscopy (PALM), stochastic optical reconstruction microscopy (STORM), and minimal photon fluxes (MINFLUX) microscopy as well as a compilation and discussion of the main fluorophores used in these techniques, the recent advances, microscope systems, challenges, and future perspectives of SRM in the food science. This review provides significant insights into SRM techniques, operation principles, recent advances, and applications in food materials. This contribution can be considered a brief guide for introducing non-experts in the food area to the knowledge of SRM techniques and contains useful information for experts in fluorescence and confocal microscopy interested in the use of SRM.