Cxvii. Observations on Some Alcohol- Soluble Proteins from Milk

THE presence of alcohol-soluble proteins in milk or cheese has been reported by several workers. Weidemann [1882] isolated from Emmenthal cheese by extraction with boiling ethyl alcohol a substance which he called caseoglutin. This was confirmed by Rose and Schulze [1884] and Benecke and Schulze [1887]. Winterstein and Th6ni [1902], Winterstein [1904] and Bisegger [1907], also working with Emmenthal cheese, concluded that caseoglutin is formed during the ripening process. Nierenstein [1912], working with old Cheddar cheese, isolated from 6874 g. of cheese 82 g. of dried caseoglutin containing 14*52 % N. Osborne and Wakeman [1918] isolated from caseinogen prepared from milk a protein which was soluble in 50-70 % alcohol and very dilute acetic acid and gave a voluminous precipitate with potassium ferrocyanide. The tryptophan, Millon and biuret reactions were strongly positive. The phosphorus content was much less than that of caseinogen, and less arginine, histidine and lysine were found on hydrolysis. Anaphylactic reactions showed no genetic relationship between caseinogen and this alcohol-soluble protein. Grimmer and Wagenfiihr [1925] and Grimmer and Schutzler [1926] concluded from the analysis of the extract from Backstein cheese with 70 % alcohol that the caseoglutin obtained was a mixture of various substances, and that the composition was very variable.