nutritional and functional properties of whey and lactose

NUTRITIONAL PROPERTIES OF WHEY PRODUCTS
The composition of
whey products varies
considerably, depending
on milk source and the
manufacturing process
involved. In general, whey
is rich in proteins, lactose,
minerals and vitamins.
The proteins in milk and
whey are complete and
of exceptional quality.
They contain, in varying
amounts and in the
right proportion, all the
amino acids required by
humans. They are also
readily digestible and
completely bio-available.
Clearly, whey proteins
are among the most
valuable component of
whey. In many cases,
whey products are used
for their nutritional
benefits as they are
a very cost-efficient
source of protein,
carbohydrate
and minerals
such as
calcium.
PROTEINS
The proteins in whey are easily digested
and contain all the essential amino acids
in the proper proportions, and they rate
as an excellent nutritional source.
Using the Protein Digestibility-Corrected
Amino Acid Scoring (PDCAAS) method,
whey protein rates a value of 1.0 because
it is highly digestible and it meets or
exceeds the recommended amount
of each essential amino acid.
Using another method to measure
protein quality—the Protein Efficiency
Ratio (PER) value—whey also ranks high
on the scale. The higher the PER value,
the better the protein. Casein, the reference
protein, has a PER value of 2.5.
Proteins with a PER greater than 2.5
are considered to be quality proteins.
Whey protein, with a PER greater than
3.0, is considered to be a nutritionally
excellent protein.
Figure 3
Essential amino acid profile of sweet whey proteins
and nutritional requirements of selected groups (FAO/WHO)
Essential Amino Acids
Valine
Tryptophan
Threonine
Phenylalanine.+Tyrosine
Methionine.+Cystine
Lysine
Leucine
5
9
11
13
17
16
19
19
22
24
35
34
41
Virtually every amino acid present in
sweet-type whey exceeds Food and
Agriculture Organization/World Health
Organization (FAO/WHO) nutritional
intake recommendations, both for
children aged 2 to 5 and for adults
(see Figure 3). In many cases, for adults,
whey proteins offer more than double
the minimum FAO/WHO standards.
59
58
62
63
66
68
88
Whey Powder
Child, 2-5 years
Adult
103
Isoleucine
13
28
59
Histidine
20
19
16
0
20
40
60
mg/g Crude Protein
80
100
120
Source: Glass, L. and T.I. Hedrick. FAO/WHO. 1976
34
e34