Page 285 - Analytical method for food addtives

17

E432–6: Polysorbates

17.1 Introduction

The major food groups contributing to dietary intake of polysorbates are
confectionery, ices, desserts, fine bakery wares, milk analogues, emulsified sauces,
chewing gum, fat emulsions for baking and dietary supplements with the maximum
permitted level of 10 000 mg/kg being allowed in fat emulsions for baking. The
acceptable daily intake (ADI) for polysorbates is 10 mg/kg body weight.
Polysorbates are non-ionic emulsifying agents formed by copolymerising
sorbitan anhydride and 20 moles of ethylene oxide. A fatty acid is esterified to one
terminal hydroxyl group of the polyoxyethylene-oxide side chain. The type of the
attached fatty acid molecule is reflected by the numbers in the names of polysorbates: 1

E432 polyoxyethylene sorbitan monolaurate (polysorbate 20)
E433 polyoxyethylene sorbitan monooleate (polysorbate 80)
E434 polyoxyethylene sorbitan monopalmitate (polysorbate 40)
E435 polyoxyethylene sorbitan monostearate (polysorbate 60)
E436 polyoxyethylene sorbitan tristearate (polysorbate 65)

17.2 Methods of analysis
There are several methods published for the determination of polysorbates in
2,3
foodstuffs. The early methods developed for polysorbates were gravimetric and
4–6
later colorimetry with confirmation by TLC and gas chromatography. More
7
recently HPLC methods have been developed. A summary of these methods is
given in Table 17.1, together with the matrices for which the methods are
applicable. If statistical parameters for them were available these have been