232. A simple and accurate viscosimetric form of rennet test

Abstract

1. Some existing types of rennet tests are briefly reviewed.2. A viscosity type of rennet test is described and results from its use are given.3. A mathematical treatment of the problems involved is given, which leads on to4. Construction of graphs showing progressive variation in “Dying away of amplitude”, “Logarithmic decrement” and “Viscosity coefficients” of milk under the action of rennet. Since viscosity determinations on liquids and gases have been commonly carried out with a disk type of viscosimeter, such a type is now introduced and similar graphs constructed from observations during its use. A close similarity in graphs to those furnished by the cylinder type of viscosimeter is obtained. The cylinder type of apparatus, we find, is more convenient in use with milk in reference to rennet action.5. Arising from the graphs a more precise method of terminating a rennet test with the present type of apparatus is indicated.

718. Renneting and the caseinate particle: a viscometric study

“…Following 5 min. of stirring, the solution was brought to pH [6][7][8] with N/1 NaOH and then heated quickly to 80° C. to inactivate native proteases of the milk (13). This process generally removed the alcohol and acetone and brought into solution any undissolved particles.…”

“…Viscometric analyses have been used to measure the rate of clotting of milk (3,4,5,6,7) and to gain specific information about the phases of the renneting processes. On the basis of viscometric study of solutions of casein in NaOH, Jirgensons (8) suggested that casein particles decreased in symmetry (i.e.…”

634. The determination of the coagulating power of commercial rennet extracts using an automatic tester

“…Similarly, an automatic coagulation time recorder was developed modelled on the principle used by Randall (2) in an apparatus for testing heparin. This instrument promised considerable advantages in convenience and accuracy over previously described forms of apparatus (3,4,5,6,7,8,9).…”