TY - JOUR

T1 - Atomic Force Microscopy study on the effect of different lecithins in cocoa-butter based suspensions

AU - Middendorf, Dana

AU - Bindrich, Ute

AU - Mischnick, Petra

AU - Juadjur, Andreas

AU - Franke, Knut

AU - Heinz, Volker

N1 - Funding information: This research project was supported by the German Ministry of Economics and Energy (via AiF) and the FEI (Forschungskreis der Ernährungsindustrie e.V., Bonn). Project AiF 16757 N. The authors are also grateful to Asylum Research, CA, USA for providing the ZTherm Kit for thermal analysis with AFM. In addition, the authors like to thank SternChemie GmbH & Co. KG, Hamburg, Germany for providing a the sunflower lecithin, Storck GmbH & Co. KG, Halle, Germany, for providing CB, as well as Lindt & Sprüngli (Kilchberg, Switzerland) for delivering soy lecithin.

PY - 2016/6/20

Y1 - 2016/6/20

N2 - 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.

AB - 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.

KW - Atomic Force Microscopy

KW - Chocolate

KW - Force spectroscopy

KW - Lecithin

KW - Phopholipid

KW - Sucrose

UR - http://www.scopus.com/inward/record.url?scp=84962669168&partnerID=8YFLogxK

U2 - 10.1016/j.colsurfa.2016.03.057

DO - 10.1016/j.colsurfa.2016.03.057

M3 - Article

VL - 499

SP - 60

EP - 68

JO - Colloids and Surfaces A: Physicochemical and Engineering Aspects

JF - Colloids and Surfaces A: Physicochemical and Engineering Aspects

SN - 0927-7757

ER -