Abstract
The hide of an animal previously used for leather may be upgraded in value through its expanded use as a food additive. While not a complete protein, collagen — the main protein of hide — may provide desirable functional properties within a food system. This protein is now abundant and will increase as new forms of meat become prevalent. Along with hide, collagen is being generated from hand‐separated meat for restructuring, desinewed meat, and bone. This review paper is designed to learn more about the effect of animal age, species, breed, sex, and nutrition on hide collagen. There is general agreement that age not only causes an increase in physical strength of the collagen fiber, through altering the degree of cross‐linking, but the quantity of soluble and insoluble collagen also changes.