54 Chapter 2
example, butter sheets are easily applied in
layered bakery products such as croissants
and Danish pastries, whereas large butter
blocks are diffi cult to handle and require
tedious wire cutting. Butter sheets are conve-
nient, thin, and individually pre - wrapped;
however, they must be handled carefully to
minimize melting during layering. A major
defi ciency of bulk butter is its high melting
point; however, fractionated milk fat technol-
ogy allows butter to be fractionated and the
fractions reworked to produce functionally
superior milk fat.
For example, soft butter oil has a melting
point of 21 ° C to 28 ° C and is used in butter
shortbread manufacture to inhibit winter
bloom. Soft butter oil improves mouth feel,
viscosity, and emulsion stability in sauces,
soups, and cream liqueurs. The hard butter
fraction, with a melting point of 42 ° C, is used
as confectionery butter to replace cocoa
butter in milk chocolate. Butter shortening is
produced by blending the hard milk fat frac-
tion with standard butter oil. It has a melting
point of 38 ° C and improved plasticized
texture, and is used in cookies and muffi ns.
A liquid form of butter shortening is made by
blending butter shortening with fresh cream.
It has a high melting point (38 ° C) with supe-
rior creaming properties. Mechanical treat-
ment and fractional crystallization allow
texture modifi cation in milk fat and this is
used in the development of dairy spreads and
in color control (e.g., white fat in cheese and
coffee whiteners).Proteins
Casein contains strongly hydrophobic regions
and random coils, and is heat stable but not
acid stable. Whey proteins are globular,
helical structures containing hydrophilic and
hydrophobic residues and are susceptible to
heat denaturation, but they are stable under
mild acidic conditions.
Functional milk proteins include casein,
caseinate, whey protein concentrate, totalpeptides can be antagonists that are ligands,
which bind to receptors without causing a
cellular response; however, they inhibit ago-
nists binding to the receptors that enable a
cellular response (Teschemacher, 2003 ).
Opioid peptides that exhibit agonistic activ-
ity include casomorphins, α - lactophorin,
β - lactophorin, and serophin, which demon-
strate morphine - like effects, and opioid pep-
tides exhibiting antagonistic activity include
lactoferroxins and casoxins that are able to
suppress the activity of enkephalins (Brantl
et al., 1981 ; Meisel, 1986 ; Antila et al., 1991 ;
Tani et al., 1994 ; Rutherfurd - Markwick and
Moughan, 2005 ).
The commercial use of milk - derived bio-
active peptides is emerging due to the increas-
ing evidence that the bioactivities of peptides
derived from milk are the most potent. This
emergence is occurring in the functional food
and nutraceutical industry.
Functional Dairy Ingredients for
Food Applications
Forms
Dairy ingredients for the food industry take
a number of forms. They can be composition-
ally complete or partially rearranged (e.g.,
milk powder, butter), they can include either
one component (e.g., anhydrous milk fat,
casein) or components rearranged or reas-
sembled (e.g., varied fat percentage in
cheeses, recombined milk products), or they
can be modifi ed for specifi c purposes (e.g.,
alkali solubilized casein, physical homogeni-
zation or transformation as in the case of
lactose to lactulose).
Milk Fats
Milk fats such as butter are used as ingredi-
ents in pastry and other bakery products and
have an organoleptic advantage over plant -
derived fats. Bulk butter and butter sheets
offer functionality and convenience. For