AFM approach to study the function of PGPR's emulsifying properties in cocoa butter based suspensions

Publication date: Available online 31 December 2014 Source:Food Structure Author(s): D. Middendorf , A. Juadjur , U. Bindrich , P. Mischnick Polyglyceryl polyricinoleate (PGPR) 1 1 PGPR Polyglyceryl polyricinoleate. often is used as emulsifier in chocolate, but only little is known on the specific interactions between sucrose particles, cocoa butter and PGPR molecules. The most remarkable effect of PGPR on lipophilic suspensions is the enormous decrease in yield value compared to soy lecithin which is not yet understood. A combination of atomic force microscopy (AFM) 2 2 AFM Atomic force microscopy. , scanning electron microscopy (SEM) 3 3 SEM Scanning electron microscopy. , rheological measurements and analysis of immobilized fat content was used to reveal more details on the mechanism of function of PGPR. It was found that this mechanism is completely different to the one of soy lecithin. On sucrose particle surfaces, PGPR concentration was determined to 0.18mg/m2 whereas soy lecithin coverage was calculated to 2.69mg/m2. The interfacial layer obtained by washing separated sucrose particles with acetone contains 83.6g/100g cocoa butter which had been immobilized together with or by PGPR molecules. This interaction plays a major role in the mechanism of function of PGPR as an emulsifier. Weakly bound structures consisting of PGPR and cocoa butter were found to form pillow-like structures. They act as spacers between the sucrose particles and reduce particle-pa...
Source: Food Structure - Category: Food Science Source Type: research