522 Chapter 20
reduced calorie carbohydrate is D - tagatose,
which is manufactured from lactose. It has
prebiotic effects and is suitable for diabet-
ics. The choice of alternate carbohydrates
includes various maltodextrins to help con-
trol osmolality and sucrose to increase fl avor
acceptability and reduce non - enzymatic
browning, which can be particularly preva-
lent in products with extensively hydrolyzed
proteins or addition of free amino acids, as
previously indicated. Prebiotic carbohydrates
such as galacto - oligosaccharides or D - tagatose
(lactose based) or fructo - oligosaccharides
(sucrose based) have found applications in
these products.
Specialized carbohydrates are used for the
diabetic market to help control glycemic
response. These can include carbohydrates
that are somewhat resistant to enzymatic
digestion, reducing the rate of monosaccha-
ride delivery to the bloodstream, and carbo-
hydrates that induce a large viscosity change
when acidifi ed (as in the stomach) and thus
slow GI passage and digestion rates. Finally,
some forms of enzyme inhibitors are at least
under development; these would alter the
body ’ s ability to rapidly digest and absorb
carbohydrates. This could be somewhat dif-
fi cult to deliver from a practical point of view
because there is a fairly wide variability in
digestive enzyme levels, even in normal
healthy adults, which can be exacerbated in
the presence of certain disorders.
A wide variety of fat systems are used in
these products. Usually they are derived from
vegetable sources for the majority of the fat
calories, and supplemented with sources of
mono - and polyunsaturated fats (certain seed
and marine oils). The goal is caloric enrich-
ment without substantial cholesterol addition
and avoidance of highly saturated fat systems.
However, the products include reasonable
levels of unsaturated fats with attention paid
to appropriate levels of specifi c kinds of
polyunsaturated fatty acids (PUFAs).
Reasonable levels of omega - 3 and omega - 6
fatty acids and appropriate concentrationhealth conditions such as renal disease
or diabetes, or have special dietary needs
such as those in critical care.- Performance nutrition products: Provide
support to recover and/or enhance perfor-
mance in sports or exercise endurance. - Healthy living products: Help manage
health proactively to prevent diseases
later in life. Examples include products
designed for maintaining healthy blood
lipids and immune benefi t; these may be
meal enhancers or meal replacements.
Nutritional products are available for chil-
dren with normal or challenged digestive sys-
tems, generally healthy adults, physically
active sports enthusiasts, adults with diseases
that require specifi c nutritional formulas (par-
ticularly the elderly), and for many others.
Typically, products for adult applications
use protein systems with combinations of
casein or milk, soy, and demineralized whey
proteins. The combinations are adjusted
to optimize fl avor, nutrition, physical appear-
ance, and cost. As the total protein level
increases, partially hydrolyzed proteins are
used for viscosity reduction. The degree of
hydrolysis is often limited by fl avor con-
straints. Other proteins (in partic ular wheat
gluten and its hydrolysates) also can be
introduced when special needs dictate nutri-
tion enriched with a particular amino acid
(e.g., glutamine or arginine) or combina-
tions of amino acids (e.g., branched - chain
amino acids). The best known among these
are diets enriched in glutamine or arginine
for special use in critical care situations
and protein supplements with high levels
of branched - chain amino acids (leucine,
isoleucine, and valine) for sports protein
supplements.
Reduction of lactose is commonly pre-
ferred for the adult population due to some
degree of lactose intolerance. The level of
acceptable lactose dictates whether casein-
ates, milk protein isolates, or milk protein
concentrates are used. One example of a