Dairy Ingredients for Food Processing

126 Chapter 5

Technologies for Manufacture of

Condensed and Evaporated Milks

Evaporation is used to concentrate milk

before drying or transportation. If milk is to

be transported long distances, it is concen-

trated to 30% to 38% TS to reduce transpor-

tation costs. Evaporation is one of the most

energy - intensive processes in the dairy indus-

try. Hence, modern evaporators are effi -

ciently designed for low energy consumption

and to provide minimal heat damage to milk

components.

There are basically two types of evapora-

tor designs — tubular and plate — that may be

single effect or multiple effects of two or

more units. Listed below are various com-

mercial types of evaporators.

The following food additives are allowed
when used at levels permitted by good manu-
facturing practices: fi rming agents (potas-
sium or calcium chloride, used at a rate of
2 g/kg singly or 3 g/kg in combination); sta-
bilizers (sodium, potassium, or calcium
citrates, used at a rate of 2 g/kg singly or 3 g/
kg in combination) or acidifi ers (e.g., phos-
phates and carbonates of sodium, potassium,
or calcium); di - , tri - , and polyphosphates
(used at rate of 2 g/kg singly or 3 g/kg in
combination); carageenan (150 mg/kg) as a
thickener; and lecithin as an emulsifi er.
CODEX standards allow for four types of
sweetened condensed milk (Table 5.2 ).
The average compositions of evaporated
and sweetened condensed milk compared to
whole milk are given in Table 5.3.

Table 5.2. CODEX standards for different sweetened condensed milks.

Sweetened

condensed milk

Sweetened

condensed

skim milk

Sweetened

condensed partly

skimmed milk

Sweetened

condensed

high - fat milk

% Fat 8 1 More than 1 to

less than 8

16

% Milk - solids - not - fat Not specifi ed Not specifi ed 20 14

% Milk solids * 28 24 24

% Milk protein in

milk - solids – not – fat *

34 34 34 34

• Milk solids and milk - solids - not - fat content include water of crystallization of lactose.
  Farkye (2008)

Table 5.3. Proximate composition of whole, evaporated, and

sweetened condensed milks.

Component Whole

milk

Evaporated

milk

Sweetened

condensed milk

% Protein 3.2 7.0 8.2

% Moisture 88 74 26

% Fat 3.5 7.5 8.0

% Carbohydrates 4.6 9.6 55.1

% Lactose 4.6 9.8 10 – 12

% Sucrose 44 – 46

% Ash 0.7 1.5 1.8

Calcium (mg) 120 228 238

Phosphorus (mg) 90 213 236

Sodium (mg) 53 94 88

Potassium (mg) 136 297 360

Farkye (2008)