Influence of sodium dodecyl sulphate concentration on disperse and rheological characteristics of oil-in-water emulsions stabilized by OSA starch-SDS mixtures

• Main Authors: Krstonošić Veljko, Dokić Ljubica, Nikolić Ivana, Dapčević Tamara, Hadnađev Miroslav
• Format: Article
• Language: English
• Published: Serbian Chemical Society 2012-01-01
• Series: Journal of the Serbian Chemical Society
• Subjects: O/W emulsions; OSA starch; SDS; rheology; disperse characteristics
• Online Access: http://www.doiserbia.nb.rs/img/doi/0352-5139/2012/0352-51391100150K.pdf

Stability of oil-in-water emulsions can be achieved by chemical modified starch, such as octenyl succinic anhydride (OSA) starch, as emulsifier. In order to analyse disperse and rheological characteristics of emulsions containing two kind of emulsifiers, part of the OSA starch can be substituted with adequate concentration of sodium dodecyl sulphate (SDS), which is small surfactant with same charge as OSA starch. Oil contents of examined emulsions were 5, 20 and 50%. Selected OSA starch concentration was 10% and replacements of the part of OSA starch were realized with SDS concentrations of 1, 3 and 5%. Dispersed droplets of emulsions were defined by determination of Sauter mean diameter d32 and particle size distribution. Flow curves were used to describe rheological properties of the emulsions. Also, stability of emulsion samples was observed and expressed by the creaming index. Obtained results indicated decrease in Sauter mean diameter of droplets, standard deviation and apparent viscosity of emulsions while amounts of SDS increase within emulsifiers mixture OSA starch-SDS. The emulsions with OSA starch according to creaming rate were more stable than emulsions stabilized by OSA starch and SDS combination.