CHAPTER 8: Imaging Nanostucture

Food structure is based on a system of molecules that provide form and function. A better understanding of the arrangement of the underlying molecules that contribute to the macromolecular structure of natural foods leads to the ability to create novel food products. Microscopes give us the opportunity to image the basic architectural molecules and are tools that contribute to research into food structure. Imaging of food at a nanostructure level is possible by the use of the transmission electron microscope, the scanning electron microscope, and the atomic force microscope. The ability of these instruments to provide nanostructure resolution is based on design principles, and the quality of the preparation of the sample. The critical objective of sample preparation is to maintain the original properties of the biological material, whether it is native tissue or a complex emulsion. Only when the sample is prepared without distortion can the interpretation be considered valid. The researcher must understand the opportunities and limitations that come with each imaging method. Cryo-preparation methods are preferred for food imaging applications because freezing preserves water, fat, and air and the distribution of these constituents, which are major components in most food systems. Imaging methods must be complemented with other scientific methods to verify interpretation and eliminate bias. Correlated microscopy techniques are recommended.