Dairy Ingredients for Food Processing

Whey-based Ingredients 191

applications such as sports and nutritional

supplements including beverages, sports

gels, and nutrition bars.

Whey Fractions

Lactoferrin is a natural glycoprotein with

iron - binding capacity. It is produced by

means of ion exchange from either skim milk

or whey. Because of its sensitive biological

properties, it is normally freeze dried

(Affertsholt and Nielsen 2007 ).

Lactoperoxidase is a natural preserva-

tive that has antimicrobial activity (Abd El -

Salam et al. 2009 ). This fraction has yet to

achieve the same commercial success as

lactoferrin.

Immunoglobulins are transporters of anti-

bodies against harmful microorganisms such

as viruses and bacteria. The main source of

commercial immunoglobulins is colostrum, a

pre - milk fl uid from the cow.

α - Lactalbumin is isolated from whey by

chromatography. It is present in both human

milk and bovine milk and as such is a benefi -

cial ingredient in infant formula (Huffman

and Harper 1999 ). It is a fully soluble protein

and the main source of tryptophan, which is

the precursor of neurotransmitters such as

serotonin, norepinephrine, and dopamine. It

is believed to help in regulating appetite,

mood, and sleep (Affertsholt and Nielsen

2007 ).

ultrafi ltration, evaporation, and drying. The
purifi cation of whey proteins by microfi ltra-
tion is based on the size difference between
fat and protein. The isolation of whey pro-
teins by ion exchange is based on the ampho-
teric nature of proteins; they can be adsorbed
onto a porous, solid phase with a surface
layer of charged groups, and then desorbed
by an appropriate pH shift to lower the
charge - charge attraction between the protein
molecules and the ion exchanger (Ayers and
Petersen 1985 ).
The difference between WPIs produced
using microfi ltration and those produced
using ion exchange chromatography is given
by their protein and mineral compositions.
The main difference in protein composition
relates to the absence of glycomacropeptides
from WPI produced by chromatography
(Table 8.5 ).
The isolation of whey protein by microfi l-
tration directly from milk is recent, i.e., since
2000 (Marcelo and Rizvi 2008 ). This process
produces a milk stream for whey - reduced
cheese milk and cultured products and a WPI
ingredient for beverages. Like the ion
exchange WPI, this whey ingredient does not
contain glycomacropeptides or peptide frag-
ments derived from cheese or casein manu-
facture. However, the membranes allow for
some casein transmission (Table 8.5 ).
Because of the relatively high costs of
WPIs, they are used mainly in premium

Table 8.5. Typical protein and mineral composition of WPI.

Component Microfi ltration

WPI

Ion exchange

WPI

% α - Lactalbumin 15 – 22 14 – 26

% β - Lactoglobulin 56 – 60 66 – 75

% Bovine serum albumin 1 – 2 3 – 6

% Immunoglobulins 2 – 5 2 – 3

% Glycomacropeptides 20 – 26 Not detected

% Lactoferrin 0 – 0.1 Not detected

% Peptide fragments 3 – 5 Not detected

% Calcium 0.3 – 0.6 0.08 – 0.11

% Sodium 0.2 – 0.3 0 – 0.5

Adapted from Huffman and Harper (1999) , Abd El - Salam et al. (2009)