Many processed foods lack the structural integrity associated with biological tissue so that the conventional methods of preparation and staining used in light microscopy may introduce misleading artifacts.
Taking as examples of starch-based processed foods, potato chips (UK potato crisps) and three distinct potato snack foods, methods for preparing and demonstrating the constituents present in cryosections of whole and masticated products are discussed. To show constituents in their true relative locations vapor staining and polarized light are used. Iodine vapor staining indicates the extent of starch gelatinisation in the dry snack and it is also used to show the structural changes that occur on mastication. Osmium tetroxide vapor colours the liquid fats and polarized light indicates the presence of crystalline fats and intact starch granules.
Flint, F. Olga
"Light Microscopy Preparation Techniques for Starch and Lipid Containing Snack Foods,"
2, Article 5.
Available at: http://digitalcommons.usu.edu/foodmicrostructure/vol1/iss2/5