Introduction Methods of analysis Recommendations

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 mgkg being allowed in fat emulsions for baking. The acceptable daily intake ADI for polysorbates is 10 mgkg 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 foodstuffs. The early methods developed for polysorbates were gravimetric 2,3 and later colorimetry with confirmation by TLC and gas chromatography. 4–6 More recently HPLC 7 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 summarised in Table 17.2. There are no recent methods of analysis for polysorbates in foods but some are available for polysorbates in biological samples and in pharmaceutical preparations.

17.3 Recommendations

Gravimetric and colorimetric methods are available for the analysis of polysorbates in foods and an HPLC method has been developed for powdered soup. These methods need to be further developed for other foodstuffs and for all polysorbates. The majority of methods available for foodstuffs are for polysorbates 60 and 80.

17.4 References