Dairy Ingredients for Food Processing

Nutritive and Health Attributes of Dairy Ingredients 405

Lactoperoxidase breaks down hydrogen

peroxide and exerts an antibacterial effect.

Therefore, it is considered to be a natural

preservative. Lysozyme displays antimicro-

bial activity against Gram - positive bacteria

and acts by lysing cell walls. Lysozyme may

indirectly affect the defense systems as an

immunomodulator through the stimulation of

immune system by breaking down products

of the cell wall (peptidoglucan). The nutri-

tional role of the milk enzymes is question-

able because they are destroyed by heat

treatment in milk processing.

Milk Fat

Many foods contain lipids in varying degree.

Table 16.15 shows the fat contribution from

major food groups in the U.S. food supply.

Clearly, each food groups provides fat in our

diet. However, most of the fat intake in 2005

was attributed to shortening (25.6%); salad,

cooking, and edible oils (25.1%); and meat,

poultry, and fi sh (23.3%). Food groups such

as fruits, vegetables, legumes, and grains

contribute minor levels of fat to our total fat

intake. Most nutritionists recommend that

daily fat intake not exceed 30% of all calories

consumed, which amounts to a daily con-

sumption of a maximum of approximately

68 g of fat in a 2,000 - calorie diet.

host against invading pathogens. In addition
to the antibacterial effect in the gut of the
calf, a nutritional role in iron metabolism has
also been ascribed to lactoferrin. Its iron -
binding characteristic aids in enhancing iron
absorption. It stimulates and protects cells
involved in the host defense mechanism by
controlling cytokine response.

Biologically Active Peptides from
Whey Proteins

As shown in Table 16.14, a number of pep-
tides derived from whey proteins exert physi-
ological activity. The bioactive peptides of
whey proteins have been shown to positively
infl uence body composition, satiety, and
weight management. In addition, the bioac-
tive peptides are ACE - inhibitory.

Milk Enzymes

Milk is a repository of a variety of enzymes;
more than 60 indigenous enzymes have
been reported in cow ’ s milk. They are
either associated with the milk fat globule
membrane (xanthine oxidase, sulfhydryl
oxidase, and γ - glutamyltransferase), skim
milk serum (catalase, superoxide dismutase),
or micelles of casein (plasmin and lipopro-
tein lipase).

Table 16.15. Percentage of contribution of fat from major food groups in the U.S. food supply from
2001 to 2005.

Food group 2001 2002 2003 2004 2005

Butter 2.6 2.4 2.5 2.5 2.4

Margarine 4.1 3.5 2.9 2.9 2.1

Shortening 23.5 22.6 22.3 22.6 25.6

Lard and beef tallow 3.0 3.2 3.4 3.3 3.5

Salad, cooking, and other edible oils 25.6 26.9 27.3 27.7 25.1

Meat, poultry, and fi sh 20.4 21.7 21.6 20.2 23.3

Eggs 2.1 2.0 2.0 2.0 1.9

Legumes, nuts, and soy 3.7 3.5 3.8 4.0 3.5

Grain products 2.4 2.2 2.3 2.3 2.2

Fruits 0.5 0.5 0.5 0.6 0.5

Vegetables 0.5 0.4 0.4 0.5 0.4

Sugars and sweeteners 0 0 0 0 0

Miscellaneous 1.1 1.0 1.0 1.1 1.1

Adapted from Hiza, Bente, and Fungwe (2008)