title: Interfacial behaviour of sodium stearoyllactylate (SSL) as an oil-in-water pickering emulsion stabiliser.
abstract: The ability of a food ingredient, sodium stearoyllactylate (SSL), to stabilise oil-in-water (O/W) emulsions against coalescence was investigated, and closely linked to its capacity to act as a Pickering stabiliser. Results showed that emulsion stability could be achieved with a relatively low SSL concentration (≥0.1 wt%), and cryogenic-scanning electron microscopy (cryo-SEM) visualisation of emulsion structure revealed the presence of colloidal SSL aggregates adsorbed at the oil-water interface. Surface properties of SSL could be modified by altering the size of these aggregates in water; a faster decrease in surface tension was observed when SSL dispersions were subjected to high pressure homogenisation (HPH). The rate of SSL adsorption at the sunflower oil-water interface also increased after HPH, and a higher interfacial tension (IFT) was observed with increasing SSL concentration. Differential scanning calorimetry (DSC) enabled a comparison of the thermal behaviour of SSL in aqueous dispersions with SSL-stabilised O/W emulsions. SSL melting enthalpy depended on emulsion interfacial area and the corresponding DSC data was used to determine the amount of SSL adsorbed at the oil-water interface. An idealised theoretical interfacial coverage calculation based on Pickering emulsion theory was in general agreement with the mass of SSL adsorbed as predicted by DSC.
authors: Centre for Formulation Engineering, School of Chemical Engineering, University of Birmingham, Edgbaston B15 2TT, UK. Electronic address: djk080@bham.ac.uk.
authors: D
authors: D
authors: Kurukji
authors: R
authors: R
authors: Pichot
authors: F
authors: F
authors: Spyropoulos
authors: I T
authors: IT
authors: Norton
mesh_terms: D002152:Calorimetry, Differential Scanning; D004655:Emulsions / Q000138:chemical synthesis / Q000737:chemistry; D010938:Plant Oils / Q000737:chemistry*; D013228:Stearates / Q000737:chemistry*; D000074242:Sunflower Oil; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: D004655:Emulsions; D010938:Plant Oils; D013228:Stearates; D000074242:Sunflower Oil; D014867:Water; C031568:stearoyl-2-lactylic acid
keywords: DSC; Interfacial coverage; Lipid particle; Melting enthalpy; Pickering emulsion; SSL; Sodium stearoyllactylate; Surface coverage; Surfactant