鶏肉の鮮度低下に伴う酸性物質と塩基性物質の消長について

　鶏肉の鮮度低下に伴って生ずる酸性物質と塩基性物質を，コーニソシュ系ブロイラー(10週令)の胸筋および腿筋について測定した.胸筋については同時に筋グリコーゲン量を測定し，初期の酸性物質との関係を検討した.
1) 酸性物質の生成量は胸筋，腿筋いづれも死後1時間目が最大であった.両筋の酸性物質は漸次減少の傾向を示したが，腿筋の酸性物質は初期腐敗後一時増加した.
2) 塩基性物質は胸筋，腿筋いづれも死後漸増し， 17 時間で200mglこ達した.此の時期は初期腐敗と認められた.
3) 胸筋グリコーゲンは1時間または2時間で死直後の30%に減少し， 3時間または5時間で消失した.

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.