The formation of lactic acid in the muscles in the frozen state

Abstract

Lactic acid accumulates in gastrocnemius muscles of the frog, kept in the frozen state in air at temp. between[long dash]0.42[degree] C. and[long dash]10[degree] C, eventually reaching a concentration of 0.75%. The rate of accumulation rises to a maximum at[long dash]2.5[degree]C., at which temp. 0.55% of acid is produced in 24 hrs. Muscles kept for 24 hrs. at temperatures above[long dash]1.6[degree] C. recover physiological properties on thawing, and are able to remove accumulated lactic acid, but below this temp. the muscle sustains irreversible damage, and passes into rigor on thawing. The effect is to be attributed to desiccation of the muscle rather than to mechanical injury or O deficiency.