Types of Protein

From the cook’s point of view there are two classes of protein, fibrous and globular. The difference lies in the way the long molecules are arranged. In a fibrous protein the chains lie lengthways like the strands of a rope. Examples are myosin, one of the chief proteins in muscles; and collagen, the main component of connective tissue such as cartilage. In a globular protein the chains are loosely bundled. Examples are ovalbumin, the main constituent of egg white; and casein in milk. All protein structures include a good deal of water, which makes up about three-quarters of the weight of muscle. A fibrous protein holds the water in a rigid network of strands. Globular proteins are dispersed in water, forming a thick liquid.