Chemical Characterization of Sorbitan Tri‐Stearate Commercial Samples and Their Determination in Confectionery Fats by HPLC High‐Resolution Mass Spectrometry

Abstract

Nominal sorbitan tristearate (E492) commercial samples are widely used generally as emulsifiers and particularly as anti-bloom agents in confectionery products. In spite of this generalized use, their qualitative and quantitative evaluation is poorly documented in literature and the relative works go back to the last decades of last century. In the present work, a deep study by HPLC-High Resolution Mass Spectrometry of qualitative composition of five E492 commercial samples was made up showing a very complex pattern of stearic and palmitic acid esters with the sorbitol anhydrides, sorbitan, and isosorbide. A clear distinction of sorbitan mono-, di-, tri-, and tetra-esters, of sorbitol penta-and hexa-esters and isosorbide mono-and di-esters was achieved. Contemporarily, difference in the qualitative pattern between E492 commercial samples coming from different suppliers was established. As a consequence, quantitative evaluation can be reliably obtained by using as calibration standard the same E492 present in real samples. The accuracy and recovery of the method were determined allowing in this way a reliable application to commercial confectionery products. The detailed knowledge of STS composition may be of great help to orient the synthesis conditions in order to modulate its properties as a function of various experimental necessities.