Relations between Freshness and Behavior of ATP Related Substances in Chicken Muscle

Abstract

Chicken muscles lose their freshness faster than beef or pork, which largely affects its quality. Therefore, by measuring changes of pH, volatile basic nitrogen, amino type nitrogen, live bacteria count and K value of chicken muscles in storage, adequate indices of chicken freshness were examined. As a result, it was concluded that K value obtained by qualitative changes of ATP related substances constituted an effective marker indicating chicken freshness, by considering that K value changes to a greater extent than the other measurement items and that it begins to increase from its slaughten on. At higher temperatures in storage, K value was increased more quickly. However, when chicken muscles were stored at -30°C, K value did not show a great change for a year. The phosphatase activity of thigh muscles was higher than that of breast muscle. In thigh muscle which is consisted of musculus complexes, K value varied according to muscular sites in storage, showing a faster increase in more reddish muscle. Change in K value was compared among chicken species (broiler, hen, japanese game) as well as between sexes in storage, but there was not difference between them.