Biochemistry of meat hydration.

Publisher Summary This chapter is concerned with the meat of mammals. Studies on the water-holding capacity (WHC) of the flesh of poultry and fish are also taken into consideration. Binding of water by muscle proteins and water-holding capacity of meat have been described. Methods appropriate for study of the WHC concern differences in the immobilization of “free” water. Most such methods are based on measuring the loose water liberated by applying pressure on the muscle tissue. The pressure can be produced in different ways: normal acceleration by gravity, increased acceleration of gravity, filtration, or pressing between two plates. The influence of pH on the WHC of meat has been studied because in this way the importance of protein charges to the hydration of muscle proteins is recognized. Moreover, such a study gives information of practical importance because the storage and processing of meat are usually accompanied by changes of pH. Metals such as magnesium, calcium, and zinc, which are in meat by nature, have an important influence on water-holding capacity in spite of their relatively low concentration. The chapter discusses animal factors affecting meat hydration and with respect to species, sex, age, grade, breeding, and muscle. The influence of the health, feeding, and treatment of animals during transport and before slaughtering is of importance in the hydration of muscle. Numerous experiments have been conducted on producing meat of a high pH and consequently, of a high WHC by certain treatments before slaughter in order to prevent weight losses during freezing and thawing, transport, storage, cooking, etc. Under post-mortem changes in meat hydration, effect of adenosine triphosphate, phase of rigor mortis, and phase of aging have been studied. The chapter discusses factors affecting hydration of aged meat and components of meat such as moisture proteins fat connective tissue.