An X-ray study carried out at DESY (Deutsches Elektronen-Synchrotron, a Research Centre of the Helmholtz Association) will help to improve the quality of chocolate. The study offers new insights into the formation of fat bloom, an unwelcome white layer that occasionally forms on chocolate. “Although fat blooming is perfectly harmless, it causes millions in damage to the food industry as a result of rejects and customer complaints,” explains the main author of the study, Svenja Reinke, from the Hamburg University of Technology (TUHH). “Despite this well known quality issue, comparatively little has been known until now about its root causes.” The team from TUHH, DESY and the food company Nestlé presents its findings in the journal Applied Materials and Interfaces published by the American Chemical Society.
Microscope view of fat bloom on chocolate. Credit: Svenja Reinke/TUHH
With DESY's bright X-ray source PETRA III the scientists could follow the migration of liquid fat (yellow) through chocolate live for the first time. The characteristic X-ray pattern (right) reveal details down to nanometre sizes. Credit: Svenja Reinke/TUHH
Inner structure of chocolate: liquid fats (yellow) can migrate through the mix of cocoa (dark brown), milk powder (light brown) and sugar (white). Credit: Svenja Reinke/TUHH