Understanding microstructural changes in biopolymers using light and electron microscopy

Most foods are derived from raw materials that have a well-organized microstructure, for example, cereal products from grains. Processing, including malting, milling, dough mixing, and heating, produce great microstructural changes in proteins, cell wall components, and starch. The distribution of protein within the endosperm cells, and in particular the binding of the protein matrix with small starch granules, has been studied with electron microscopy. A variety of microscopic techniques is available for studying the different chemical components of grains and cereal products. Bright-field and fluorescence microscopic methods are frequently used because they allow selective staining of different chemical components. Scanning electron microscopy is used to examine surfaces and transmission electron microscopy the internal structure of food. Malting barley is one of the most studied plants, and the structure and physiology of the germinating grain have been especially well characterized. During development of a wheat kernel, protein bodies within the endosperm cells fuse to form the protein matrix.