Chem. (Incorrectly -ine.) [f. L. case-us cheese + -IN.] A substance belonging to the class of Proteids or Albuminoids, forming one of the chief constituents of milk; chemically identical with the Legumin (also called vegetable casein), of the seeds of leguminous plants. Casein is coagulated by acids, and forms the basis of cheese.
1841. Lond. Edin. & Dub. Jrnl., Dec. No. 126. Vegetable Caseine.
1845–6. G. Day, trans. Simon’s Anim. Chem., II. 55. However much the nutriment of the mother may vary, no great influence is thereby exerted on the relative quantities of casein and sugar.
1863. Wynter, Subtle Brains & Lissom Fingers, 157. Casein, or cheese, exists more abundantly in peas and beans than it does in milk itself.
1869. Roscoe, Elem. Chem., 434. Casein is the nitrogenous substance contained in milk and cheese.
b. Jocularly for ‘the cheese,’ ‘the correct thing.’
1856. Kingsley, Lett., May (D.). Horn minnow looks like a gudgeon, which is the pure caseine.
