The amount of acidic substance and basic substance generated in the course of deterioration of freshness were measured in the breast and thigh muscles of the broiler by the method of titration in non aqueous solutions. In connection with the experiment, glycogen content and pH value in the breast muscle were also measured.
The results were as follows :
1) The amount of acidic substance generated was the highest at one hour after death in both muscles and it decreased gradually with the deterioration of freshness. After the stage of incipient putrefaction the amount of acidic substance increased temporarily in the thigh muscle only.
2) The amount of basic substance increased gradually from one hour after death and reached 200 mg per 100 g of meat at the stage of incipient putrefaction.
3) The amount of glycogen decreased to about 30 % of initial level within one or two hours and disappeared completely within three or five hours after death. The value of pH also dropped rapidly within one or two hours after death.
4) In the chicken muscles, it was presumed that the large part of acidic ~ubstance increased within one hour after death was closely related to the rapid breakdown of glycogen.