ABSTRACT
This chapter discusses collagen and gelatin together because of the close relationship between them. Gelatin is prepared from collagen on a large commercial scale to cover the needs of the photographic, food, and pharmaceutical industries. Collagen, a proteinaceous substance, is present in the mammalian connective tissue. Collagen is unique among the proteins because of its amino acid composition. The elementary basic molecular unit of collagen is tropocollagen. Collagen in the native state is associated with impurities and must be separated from them. The success of a process employing collagen as a basic material often depends upon maintaining the collagen fibril structure throughout the process. In all industrial processes for the preparation of collagen dispersions, attempts are made to minimize the degradation of collagen molecules. Electron-mi-croscopy, X-ray diffraction, the ultracentrifuge, and achievements in the field of polymer chemistry largely contributed to a better understanding of the structure of collagen, the chemistry of gelatin forming, and the tanning processes.
