426 Chapter 17
a much higher mineral content than sweet
whey. Both dry powders are approximately
12% protein and 75% lactose, which limits
their use for functionality. To further refi ne
whey, it undergoes ultrafi ltration to remove
lactose and minerals. Whey protein concen-
trates are available in various ranges of
protein, usually 35% protein (to replace skim
milk powder) and 80% protein. Whey protein
isolates have greater than 90% protein.
Modifi ed whey powders have had minerals
and lactose removed by various processes
such as ultrafi ltration or electrodialysis, and
are not necessarily sourced from cheese
whey. Chapter 8 discusses whey products in
detail.
Caseinates. Caseinates are produced by
isolating the casein proteins in milk by
methods such as acid or rennet precipitation,
or fi ltration, and then often treating to modify
protein solubility and functionality (typically
creating sodium or calcium caseinate).
Caseinates contain greater than 90% protein.
They are used extensively in coffee whiten-
ers. Because they also are extremely func-
tional emulsifi ers and foam formers, they are
very useful in mousse powder blends and
powdered coffee mixes where milk foam is
desired. See Chapter 7 for a more detailed
discussion on caseinates.Processing of Dry Mixes
Chapters 6 , 7 , and 8 in this book cover pro-
duction of dry dairy ingredients; refer to
those chapters for more information on
drying ingredients and agglomeration pro-
cesses. The considerations that are unique to
powdered mixes are presented below.Blending
The ideal way to create a powdered mix is to
mix, blend or reconstitute ingredients in
water or milk, and then pasteurize, homoge-
nize, and spray dry the blend. Further treat-
ments such as particle size enlargementphospholipids provide functional emulsify-
ing properties. The fat globule membrane
material also is associated with bioactive
attributes from some of its components;
Dewettinck et al. (2008) is an excellent
review. Because of its fat content, the shelf
life of buttermilk powder is less than that of
nonfat dry milk, typically six to nine months.
Lactose. Lactose is the disaccharide natu-
rally found in milk. It is commercially pro-
duced by removing the lactose from whey
when whey is refi ned to concentrate the pro-
teins by ultrafi ltration. The liquid containing
the lactose is condensed, and the sugar is
allowed to crystallize by gradually cooling
the liquid. The crystals can then be further
treated by grinding and classifying by granule
size (unground, medium, fi ne) or they can be
washed to remove ribofl avin, minerals, and
remaining protein to create “ refi ned ” lactose.
It is added to formulas to increase the solids
level without greatly increasing sweetness. It
also participates in browning reactions
through both the Maillard reaction and car-
melization. Like other sugars, lactose can
help disperse other ingredients such as milk
powders and stabilizers, making them easier
to reconstitute. Lactose improves dispersibil-
ity by physically separating ingredients in a
dry blend and adding density to the mix to
help with sinkability during reconstitution, or
by helping to form complexes during agglom-
eration processes that improve dispersibility.
Chapter 6 of this book deals with dry milk
products in detail.
Whey. Whey - based ingredients can take
the form of sweet or acid dried whey, whey
protein concentrate, whey protein isolates,
and modifi ed whey powers. Lower protein,
less refi ned products (sweet or acid whey) are
inexpensive sources of solids, whereas whey
protein concentrates and isolates are added to
foods as protein sources and for their protein
functionality. Whey is the waste product
from cheese making. Depending on the type
of cheese (acid - vs. rennet - coagulated), the
whey is either acid or sweet. Acid whey has