casein molecule into two similar molecules of paracasein; perhaps
in somewhat the same manner that maltose is split into two
molecules of dextrose.
Second, that, as a consequence of this cleavage it would seem
to be doubtful if Hammarsten’s whey-protein could be one of the
products of rennin action.
Third, that rennin is not, strictly speaking, a coagulating ferment,
the coagulation of paracasein being due to the fact that
calcium paracaseinates are less soluble than the calcium caseinates,
especially in the presence of soluble salts of calcium, barium or
strontium.
This investigation was undertaken as an attempt to determine
the truth of these statements. In repeating the work of Hammarsten
and others a soluble substance which had not been. coagulated
by rennin and could not be precipitated by dilute acetic
acid was always found in the filtrate. Casein solutions for such
investigations have been prepared, as a general rule, by shaking
pure casein with an excess of lime water or by grinding with moist
calcium carbonate. The casein solutions thus obtained were made
neutral to litmus and coagulated by the addition of rennin. The
curds were filtered off and the filtrates examined for nitrogen.