Dairy Ingredients in Infant and Adult Nutrition Products 519formulas designed for intolerant infants, but
these have not yet achieved signifi cant market
share.
Lactose intolerance in infants has been
addressed by use of soy protein formulas or
formulas using lactose - free or very - low
lactose dairy protein. Lactose intolerance has
been associated with fussiness and gassiness;
the incidences of true clinical lactose intoler-
ance may not be as widespread as thought.
Another breakthrough development in
recent years has been the introduction of
galacto - oligosaccarides (GOS) or transgalac-
tosylated oligosaccharides (TOS) in infant
and toddler products (Figure 20.1 ). Human
milk contains a variety of oligosaccharides,
with associated physiological benefi ts. A
review of the wide variety of structures and
their putative functionalities is beyond the
scope of this chapter; however, a few recent
reviews are listed at the end of the chapter
for further information. The functionality of
such oligosaccharides can be partially mim-
icked in infant formula by addition of GOS
to help stimulate positive bacterial growth in
the digestive tract, thus, they are termed
prebiotics.
Measurable lactulose levels can be found
in formulas, especially in retorted liquid
infant formulas that contain lactose. Lactulose
may help in softening the infants ’ stools.
However, excessive lactulose can create
intestinal disorders, and levels of this com-
pound are controlled by a combination of
formulation and processing.of acid casein and cheese making, both of
which are sources of whey protein products.
However, the whey protein materials derived
from these two sources are somewhat differ-
ent because the use of rennet in cheese pro-
duction actually hydrolyzes a peptide bond
of κ - casein, cutting the protein approxi-
mately in half, with one half carrying all of
the glycosylation of the protein. This heavily
glycosylated κ - casein fragment is called gly-
comacropeptide (GMP), and is a signifi cant
component of cheese or sweet whey. The
byproduct of acid casein as a whey protein
source produces sour or acid whey, which
does not contain signifi cant GMP.
Increasing knowledge about factors that
affect digestibility, causes of intolerance, and
milk - protein allergy has had an enormous
impact on the protein composition of infant
formulas. Partly or completely hydrolyzed
whey and milk proteins are available for
these specifi c purposes. More recent formu-
las have focused on the benefi ts of partially
hydrolyzed protein systems, promoting their
ease of digestion. These partially digested
proteins also offer a wide variety of peptides
with potential physiological benefi ts to
infants. These improvements affect the cost
of formulas, which is offset by the increased
benefi ts to infants.
Milk protein intolerance also can be
addressed by use of alternative protein
sources, most notably soy protein. Outside
the United States, other protein sources, such
as rice protein, are also used in commercial
Figure 20.1. Structure of galacto - oligosaccharides (p = 0 − 6).
OO CH 2 OHCH 2 OHO
OHHO OHOOHHOOCH 2 OHOHHOHOp