Low-fat chocolate could be a zap away

By applying an electric field to melted chocolate, confectioners could alter its microstructure in a way that enables them to reduce the fat content simply and at low cost, according to a study supported in part by Mars Chocolate (Proc. Natl. Acad. Sci. USA 2016, DOI: 10.1073/pnas.1605416113). Chocolate, which can contain as much as 60% fat, is typically processed as a liquid and solidified just before packaging. The liquid is a suspension of roughly 2-µm-wide particles, containing cocoa, sugar, and milk solids, in a base of liquid fat and oil, mainly cocoa butter. Simply removing fat from the suspension concentrates the solids, which causes the liquid to become too viscous to flow through manufacturing equipment. To bypass the viscosity problem, Temple University physicist Rongjia Tao and coworkers applied an electric field to chocolate along the direction it flowed. They found that the process aggregates the particles, forming chainlike structures several micrometers in length oriented along the flow direction. This reduced the viscosities of brandname chocolates by 40 to 50%, allowing a roughly 10% reduction in fat and yielding “wonderful tasting chocolate,” Tao says.