424 Chapter 17
itself has lower levels of sugars necessary to
participate in non - enzymatic browning reac-
tions, but ingredients added to cheese
powders such NFDM and whey contain large
amounts of lactose. The water activity and
storage temperature of the product affect the
browning reaction in cheese powders; there-
fore, formulation and distribution conditions
can be manipulated to minimize browning
(Kilic et al., 1997 ). Packaging is an important
consideration in cheese powders. The product
is often nitrogen fl ushed and stored in foil -
lined packages to reduce oxidation.Dairy Ingredients in Dry Mixes
Nonfat dry milk. NFDM is added because it
contains 35% protein in the natural propor-
tions of casein and whey proteins, and is rela-
tively resistant to lipid oxidation due to its
low fat content (less than 1.5%). Nonfat dry
milk has a shelf life of 12 to 18 months if
appropriately packaged and stored. Instan-
tized milk powder has a shorter shelf life
(about six to 12 months). NFDM is added for
whipping air into products, binding water, gela-
tion, and fl avor. It is classifi ed by the drying
method and the amount of heat applied.
As an ingredient in a dairy product, low -
heat, spray - dried NFDM is typically used
because it has the cleanest fl avor, less protein
denaturation, and less carmelization of the
lactose. High - heat, spray - dried nonfat dried
milk is used for bakery applications, and
roller - (drum) dried milk powder is used
for milk chocolate because of the extensive
carmelization of the sugars that will have
occurred.
For spray - dried milks, the American Dairy
Products Institute classifi es heat treatment as
low, medium, and high by measuring the
amount of undenatured whey protein in a
sample. As heat treatment progresses, whey
protein is denatured and becomes less soluble.
Additionally, in the United States, milk
powders are further classifi ed by the U.S.
Department of Agriculture (USDA) as extrathey do not contain all of the dairy ingredients
required for making the product, and instead
rely on the consumer to add the milk and
cream. This makes the dry mix less expen-
sive, and prevents issues common with stor-
ing dried dairy ingredients such as caking,
browning, and oxidative rancidity.
Cr è me Br û l é e manufactured by Dr. Oetker
is an example of a commercial mix that con-
tains signifi cant amounts of dry dairy ingre-
dients including whey powder (fourth
ingredient), dried cream, sodium caseinate,
and skim milk powder. Milk and cream are
added to the dry mix to make the dessert.
No - bake cheesecakes such as Jell - o No Bake
(Kraft Foods, Glenview, IL) are another
example; they contain cheese powder, casein-
ate, sweeteners, emulsifi ers, and stabilizers.
Cold milk is whipped with the dry mix, and
the blend is set by the starch and gums in the
mix.
Dry mixes are intended to have a shelf life
of at least one year at ambient conditions.
Therefore, when powdered cream, whey, and
milk powder are included in these mixes, it
is very important to package them in foil -
lined pouches, and ideally nitrogen fl ush
them.
Cheese Powders
Cheese powders are used for seasonings and
sauces in products such as packaged meals
and side dish kits, snack seasonings, dry dip
mixes, and soups. They are produced by
grinding cheese, diluting it with water, and
adding additional ingredients such as fl avors,
spices, whey, milk powder, vegetable oil,
emulsifying salts, highly fl avored enzyme
modifi ed cheese, carbohydrate - based extend-
ers (maltodextrins, corn syrup solids), anti -
caking agents, acids, and color. The mixture
is pasteurized and then spray dried.
Quality issues with cheese powders
include non - enzymatic browning as well as
oxidative rancidity due to the high level of
fat in the product (often up to 50%). Cheese