Food Chemistry

460 8 Food Additives

saponification number of the emulsifier, AV =
acid value of the separated acid):

HLB= 20

(

1 −

SV

AV

)

(8.40)

On the basis of experimental group numbers (Ta-
ble 8.21), the HLB value can be calculated using
the formula:

HLB=∑(hydrophilic group number)−

∑(hydrophobic group number)+7 (8.41)

Some examples listed in Table 8.22 show very
good correspondence between calculated and ex-
perimentally found HLB values.

Table 8.21.Group number NHand NLfor HLB calcu-
lation

Hydrophilic group NH Lipophilicgroup NL

OSO− 3 ,Na+ 38. 7 CH 0. 475
SO 3 −,Na+ 37. 4 CH 2 0. 475
COO−,Na+ 21. 1 CH 3 0. 475
COO−,K+ 19. 1 CH 0. 475
Sorbitan ring 6. 8 CHCH 2 O

CH 3

0. 15

Ester 2. 4
COOH 2. 1
OH (free) 1 .9 Benzene ring 1. 662
O 1. 3
(CH 2 CH 2 -O) 0. 33

Table 8.22.Hydrophilic lipophilic balance (HLB) val-
ues of some surfactants

HLB-value

Compound Found Calculated

Oleic acid 1. 0
Sorbitol tristearate 2. 12. 1
Stearyl monoglyceride 3. 43. 8
Sorbitol monostearate 4. 74. 7
Sorbitol monolaurate 8. 6
Gelatin 9. 8
Polyoxyethylene sorbitol 10. 510
tristearate
Methylcellulose 10. 5
Polyoxyethylene sorbitol 14. 9
monostearate
Polyoxyethylene sorbitol 15. 015
monooleate
Sodium oleate 18. 0
Potassium oleate 20. 0

Table 8.23.HLB-values related to their industrial ap-

plication

HLB-range Application

3–6 w/o-Emulsifiers

7–9 Humectants

8–18 o/w-Emulsifiers

15–18 Turbidity stabilization

The HLB values indicated the first industrial ap-

plications (Table 8.23). For a detailed character-

ization, however, comprehensive knowledge of

possible interactions of the emulsifier with the

many components of a food emulsion is still lack-

ing. Hence, emulsifiers are mainly used in accor-

dance with empirical considerations.

It has been observed with neutral emulsifiers that

the degree of hydration of the polar groups de-

creases with a rise in temperature and the influ-

ence of the lipophilic groups increases. Phase in-

version occurs o/w→w/o. The temperature at

which inversion occurs is called the phase con-

version temperature.

8.15.3 Synthetic Emulsifiers

Today, 150,000–200,000 t of emulsifiers are pro-

duced worldwide. Of this amount, mono-and dia-

cylglycerides and their derivatives account for the

largest part, i. e. about 75%. Synthetic emulsifiers

include a series of nonionic compounds. Unlike

the ionic compounds, the nonionic emulsifiers are

not in danger of decreasing in interfacial activ-

ity through salt formation with food constituents.

The utilization of emulsifiers is legislated and of-

ten differently regulated in some countries. The

synthetic emulsifiers described below are used

worldwide.

8.15.3.1 Mono-, Diacylglycerides

and Derivatives

Mono- and diacylglycerides, which are mostly

used as mixtures, are produced as described

in 3.3.2. Other emulsifiers with special activities

are obtained by derivatization (cf. Table 8.24).

As a result of the diverse reaction possibilities