Atomic Force Microscopy study on the effect of different lecithins in cocoa-butter based suspensions

authored by: Dana Middendorf, Ute Bindrich, Petra Mischnick, Andreas Juadjur, Knut Franke, Volker Heinz
Abstract: To get a deeper insight into the molecular interactions between sucrose and lecithin's different phospholipids (PL), the impact of soybean and sunflower lecithin on sucrose surfaces ground in liquid cocoa butter was studied. Therefore, flow properties of the cocoa-butter based suspension, immobilized cocoa butter content as well as detailed PL analysis concerning layer thickness and PL content was related to sucrose surface topographies and force spectroscopy measurements performed by atomic force microscopy (AFM).We found that adsorption of PL from soy lecithin to sucrose resulted in thinner layers with a larger total PL coverage, whereas PL from sunflower adsorbed in smaller amounts but resulted in thicker layers. So, PL covering of the surface is not homogeneous. As a consequence, immobilized fat content after adsorption of PL from soy was found to be smaller than for PL from sunflower lecithin. Also the yield value for suspensions containing soy PL was somewhat lower than for PL from sunflower lecithin. These changes could successfully be traced back to the microscopic scale of the sucrose particle surfaces. AFM surface properties were found to be highly influenced by adsorption of emulsifier molecules in the way that topography dramatically changed and also adhesion properties highly differed after application of soy or sunflower lecithin. By linking these molecular properties of PL from different origin to their behavior at molecular level and to the resulting macroscopic effects, the outcome of this study confirmed some essential differences between the applications of soy and sunflower lecithin with respect to chocolate manufacturing.
Organisation(s): Institute of Food Science and Human Nutrition
Food Technology Section
External Organisation(s): German Institute of Food Technology (DIL e.V.)
Technische Universität Braunschweig
Type: Article
Journal: Colloids and Surfaces A: Physicochemical and Engineering Aspects
Volume: 499
Pages: 60-68
No. of pages: 9
ISSN: 0927-7757
Publication date: 20.06.2016
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Surfaces and Interfaces, Physical and Theoretical Chemistry, Colloid and Surface Chemistry
Electronic version(s): https://doi.org/10.1016/j.colsurfa.2016.03.057 (Access: Closed)