Dairy Chemistry And Biochemistry

388 DAIRY CHEMISTRY AND BIOCHEMISTRY

Factor First phase Second phase Overall effect,

Temperature + ++ a

+++ b

+++ C

PH

Ca

Pre-heating ++ ++++ d

Rennet concentration ++++ e

Protein concentration + ++++ f

20 40 60

C

0

Ca

1 /Rennet

t ez

6.4

PH

C 65

0

% Protein

Figure 10.4 Principal factors affecting the rennet coagulation time (RCT) of milk.

flocs of protein form in the film on coagulation. Several types of apparatus
using this principle have been described.
As shown in Figure 10.3, the viscosity of milk increases sharply when
milk coagulates and may be used to determine the coagulation point. Any
type of viscometer may, theoretically, be used but several dedicated pieces