Atomic force microscopy as a tool for interpreting the rheology of food biopolymers at the molecular level

Atomic force microscopy (AFM) is still a relatively new form of microscopy. Unlike conventional microscopes the AFM generates images by feeling the su rface of the sample: the microscope senses the changes in force between the surface and a probe as the sample is scanned relative to the probe. An ana logy is a blind person who produces images by touch. Much as the blind pers on can generate images of surface shape, hardness and stickiness, so the AF M can produce images of surface topography, adhesion, elasticity or charge. This mini review will be concerned solely with topographical imaging and i ts application to study food biopolymers. Current commercial AFMs per-mit s ubmolecular resolution under gaseous or liquid environments and, under suit able circumstances, it is possible to image molecular processes in real tim e. This article is intended as a mini review of applications of AFM in food science which permit a molecular understanding of the rheology of food bio polymers. (C) 2001 Academic Press.