504 Chapter 19
Figure 19.2. Flow diagram for manufacture of crumb - based milk chocolate.
MIXINGSTORAGELECITHINLECITHINCOCOA
BUTTERCOCOA
BUTTERCRUMBCRUMB
MILLINGREFININGCONCHINGVISCOSITY
ADJUSTINGIn addition, the crumb process results in a
high degree of what is known in the industry
as free milk fat. (Campbell and Pavlacek,
1987 ). Free milk fat refers to milk fat that is
not entrapped in the milk solids matrix, and
is therefore free to mix with the cocoa butter
and cause an increase in the effective con-
tinuous phase volume. This increase can
cause a reduction in the viscosity of the
molten chocolate due to a reduction in
the number of particle interactions in the
shear fl ow fi eld.
A scanning electron micrograph of a
typical crumb chocolate is shown in Figure
19.3. The image shows two characteristic
features of crumb chocolates. First, because
many of the sucrose particles present were
formed from recrystallization of dissolved
sucrose in the milk - condensing process, geo-
metric facets can be clearly observed on the
sucrose crystals. Second, milk proteins can
be observed associated with the surface of
the crystals, rather than being present as dis-
crete particles.Dry Milk and the Milk Powder Process
The milk powder process can employ either
whole milk powder (WMP, full - cream milk
powder) or skim milk powder (SMP), or a
blend of the two. A general fl ow diagram for
production of milk power chocolate is shown
in Figure 19.4. The process fl ow follows that
described earlier, in which milk powder,
sugar, cocoa mass, and cocoa butter are
mixed, refi ned, conched, and standardized.