AFM-based local thermal analysis is a suitable tool to characterize the impact of different grinding techniques on sucrose surface properties

• Published in: Journal of food engineering 2018-10, Vol.235, p.50-58
• Main Authors: Middendorf, D., Bindrich, U., Mischnick, P., Franke, K., Heinz, V.
• Format: Article
• Language: English
• Subjects: Atomic force microscopy; Fat immobilization; Flow behavior; Grinding; Local thermal analysis; Sucrose surfaces
• ISSN: 0260-8774; 1873-5770
• DOI: 10.1016/j.jfoodeng.2018.04.021

Influence of roller and ball mill grinding technology applied for sucrose particles in a lipophilic suspension was investigated considering both particle properties and suspension's flow behavior. Especially particle surfaces after grinding were analyzed using a novel approach by combining atomic force microscopy (AFM) and AFM-local thermal analysis (AFM-LTA). This technique is able to characterize local distributions of different surface states on sucrose particles in nano- and microscale by determining local softening temperatures. For the first time, it was possible to demonstrate on molecular level that applied grinding technologies resulted in different surface characteristics with respect to adhesion forces and state of sucrose using AFM-LTA. Differences in flow behavior despite same particle size distributions and solid contents were traced back to the distribution of crystalline and amorphous areas on sucrose particle surfaces. •Lipophilic sucrose suspensions were ground by roller or ball mill to similar PSD.•AFM-LTA revealed different sucrose surface states depending on grinding process.•Different flow behavior was found related to fat immobilization on solid surfaces.•Local distribution of amorphous areas on particle correlates with flow behavior.