Dairy Ingredients for Food Processing

35

Chapter 2

Chemical, Physical, and Functional Characteristics

of Dairy Ingredients

Stephanie R. Pritchard and Kasipathy Kailasapathy

Milk

Milk is a white, lacteal secretion of the
mammary gland that provides neonates with
their required nutritional needs. It can be
obtained from mammals including humans,
cows, buffaloes, goats, and sheep. Cow ’ s
milk is the main milk consumed by humans
and it is defi ned as a whole, clean, lacteal
secretion obtained by complete milking of
one or more healthy milk animals, excluding
that obtained within 15 days before par-
turition and 15 days after calving or such
periods as may be necessary to render the
milk practically colostrum - free and contain-
ing the minimum - prescribed percentages of
milk fat and milk - solids - non - fat (SNF).
Chemically, it consists of multidisperse
phases that contain signifi cant levels of
required nutrients including fat, protein, car-
bohydrates, vitamins, and minerals.

Dairy Ingredients

Milk contains a number of ingredients that
are used in various food products due to their
characteristic properties that include the
emulsifying and stabilizing properties of
caseinates, the gelling properties of whey
protein concentrates and isolates, and the use
of lactose in confectionary products.

Milk Components and

Other Defi nitions

Several components of milk can be segre-

gated using various techniques and conse-

quently are named accordingly. Milk serum

is milk without the fat globules and casein

micelles. Milk plasma is the fl uid portion of

the milk minus the fat globules. The total

content (except water) is referred to as dry

matter. The milk - solids - not - fat content con-

sists of protein, lactose, and minerals. Total

solids include the serum solids and milk fat.

Chemical Properties of Milk

Milk constituents (protein, lipids, etc.) have

various chemical and physicochemical prop-

erties that affect their processing and func-

tional characteristics, which are signifi cant in

the production of milk - derived dairy prod-

ucts including cheese, yogurt, butter, and

cream.

Milk Composition

Milk is mainly comprised of water, followed

by lactose, fat, protein, and minerals.

Constituents of Milk

The constituents of milk are the same for all

species; however, the concentration of each

constituent varies. Legally, milk refers to

cow ’ s milk. Milk from other species must be

labeled accordingly. Table 2.1 shows the

Dairy Ingredients for Food Processing edited by
Ramesh C. Chandan and Arun Kilara
© 2011 Blackwell Publishing Ltd.