Dairy Ingredients for Food Processing

Dairy Ingredients in Infant and Adult Nutrition Products 525

and masking the bitterness associated with

their use is often very challenging; however,

they do make a softer bar. The general differ-

ence in delivering protein in bars is that bars

are usually discontinuous phase products,

comprised of the fi ller, crisps, fruit or candied

inserts, liquid fi llers, and one or more types

of coatings. There are commercial examples

of inclusion of signifi cant protein content in

virtually all of these components.

Bar hardening associated with proteins is

due to the terminal sulphur groups on the

amino acid residues forming covalent bonds.

In doing so, their net average molecular

weight is raised, increasing their glass transi-

tion. Bar hardening may still occur with

hydrolyzed proteins, but the smaller starting

molecular weight causes it to take longer to

reach the critical molecular weight that

causes hardening. Judicial use of hydroly-

sates can result in an acceptable shelf life

target. Hardening also can be minimized in

non - crisp applications using glycerin and

sorbitol, although sorbitol levels must be

controlled due to its laxative effects. Glycerin

has no laxative effects, but there are bitter-

ness issues at certain product - and formula -

dependent levels.

Technologies for Emerging

Nutritional Needs

Physiological Functionality

Physiological functionality can be delivered

by dairy - derived ingredients. One example is

the use of lactoferrin to limit infection by

limiting undesirable microbial growth via

sequestering iron and by virtue of a substan-

tial fragment, lactoferricin, which is a direct

antibiotic.

Low but perhaps signifi cant quantities of

highly biologically active proteins are found

in milk, including some very powerful growth

factors such as insulin - like growth factor,

transforming growth factor β (TGF - β ), and

immunoglobulins which function in nature to

characteristics, casein is considered a slow
protein, whey is a fast protein, and soy is
intermediate between these two. It is impor-
tant, however, to note that relatively rigorous
processing, as well as the presence of sub-
stantial fat and carbohydrates (which is very
often the case in meal - type products), may
alter digestion rates. Some also consider that
the individual differences between these
proteins are reduced or even eliminated
by such processing and delivery. Further
experimentation is needed to address these
questions.

Alternate Forms of Nutritional

Products: Bars and Gels

Broad use of semi - solid technologies has not
occurred, although nutritional bars and pud-
dings are currently widely popular, and
protein - rich gels have started appearing in
sports nutrition and “ shooter ” products,
which deliver a relatively large dose of one
or a few key ingredients in a very small
volume of gel or liquid. Gels and puddings
are typically delivered by violating one or
more of the considerations described above
for viscosity control, or by adding a gelling
agent such as one of the pectins or a modifi ed
starch. Whey proteins in particular can be
manufactured to produce gels. Defatted and
undenatured whey protein isolates are used
in high - acid drinks, creating a near clear
solution. Whey protein hydrolysis also
increases solubility.
High protein levels are obtained in nutri-
tional bars via use of protein crisps, which do
not create the shelf hardening issues observed
with direct use of protein powders during
product formulation. Crisps can contain up to
50% protein before hardness and graininess
appear. In standard bars, protein can be deliv-
ered as part of a nougat or dissolved or sus-
pended in a binder syrup. Hydrolyzed
proteins or proprietary blends of intact and
hydrolyzed proteins are used. Hydrolyzed
proteins often have signifi cant fl avor issues,