512 Chapter 19
hydrolyzed whey preparations can be suc-
cessfully used to produce a shelf - stable
product.Aerated Confectionery
An aerated confectionery product is a disper-
sion of a gas in an aqueous phase that is a
highly concentrated syrup made up from a
variety of sugars and whipping agents. The
density of the fi nished product is reduced by
the presence of gas, usually air. Nitrogen can
be used when a high amount of fat is present
(Jackson, 1990; Anon., 1994). Aerated con-
fectionery is produced by vigorous agitation
of the syrup. Stability is obtained by the addi-
tion of a whipping agent or stabilizer.
At the simplest level the air is incorpo-
rated by beating at various speeds in an open
pan. Beating creates a series of cavities which
entrap air in the form of large bubbles. While
continuing beating, the largest air bubbles are
broken into smaller units. The viscosity of
the fi nal mix increases depending on the
amount of air incorporated in the product.
Stability of the aerated confection is
obtained by the presence of high - molecular -
weight foaming agents, which create a protein
network within the foam to help stabilize the
fi nal structure. That protein semi - rigid
network is present in the syrup or continuous
phase of the confectionery which surrounds
each of the air cells (Jackson, 1990; Anon.,
1994). These protein foaming agents carry
both hydrophobic and hydrophilic groups
within their structure. The hydrophobic group
is absorbed on the surface layer of the bubble,
while the hydrophilic groups are directed to
the aqueous phase. In the next stage the
protein chains may begin to untangle and lie
along the surface fi lm. This helps to hold the
air cells in a rigid and stable network.
Common aerating proteins used in the for-
mulation of aerated confectionery include
gelatin, soy, and modifi ed dairy proteins.
Within the last category, both partially dena-
tured WPCs (80% protein) and partiallyhomogenization also helps provide well -
dispersed small fat globules. Emulsifi ers
such as lecithin (less than 1%) or mono - and
diglycerides (5% to 10% of the fat weight)
aid in producing a stable emulsion. In addi-
tion to emulsifi cation, mono - and diglycer-
ides contribute to machinability, stand - up,
and hardness of the fi nished caramel product.
Traditionally, caramel has been made
using sweetened condensed milk as the prin-
cipal dairy ingredient. Because sweetened
condensed milk is costly to ship and has a
relatively short shelf life due to its water
content, many caramel producers fi nd supply
chain effi ciencies by procuring SMP and pre-
paring a condensed milk intermediate on site
by reconstituting the milk powder.
It is advisable that powdered dairy ingre-
dients be reconstituted with warm water
(50 ° C to 60 ° C), preferably in an homoge-
nizer prior to addition to the cooking vessel.
Pre - blending of the dairy powder with some
of the formulation sugar also prevents
lumping during the recombination process. If
no homogenizer is available, the dairy ingre-
dients can be reconstituted in the following
manner. Place a pre - determined amount of
warm water heated to 72 ° C in a kettle. Slowly
add the blended dairy powders with enough
agitation to give the solution a creamy con-
sistency. Mix for at least 15 to 20 minutes. If
the recombined dairy blend shows signs of
curdling, it is advisable to add a neutralizing
agent, usually disodium phosphate at a level
of 0.01% to 0.05% of the total protein.
High - quality caramels can be produced
using sweet whey and whey protein concen-
trates as partial or total replacements of the
milk component; however, care must be
taken not to exceed the saturation point of the
lactose. In formulations with high levels of
whey components, the high level of lactose
can result in a system that is supersaturated
in lactose, and the formation of lactose crys-
tals can cause organoleptic defects over the
shelf life of the confection. In these types of
formulas, commercially available lactose -