Tempering of Chocolate in a Scraped Surface Heat Exchanger

摘要

Crystallization of dark chocolate during different tempering processes has been studied in-situ in a lab-scale Scraped Surface Heat Exchanger. The linear relationship between torque and viscosity made possible the control of chocolate crystallization during tempering by following torque variations vs. time and converting them to equivalent viscosity values. These variations of equivalent viscosity of chocolate observed during tempering were correlated with temper-meter measurements which had been related to the content of cocoa butter seeding crystals. A temper- ature cycle (50-26.1-30.5-33.3℃) enabled preparation of a well-tem- pered chocolate stable for ≥30 min at that temperature. It was characterized by a seed crystals content of about 1.15 ± 0.1/100 of cocoa butter, crystallization temperature of 23.9 ± 0.2℃ in the temper-meter and an equivalent viscosity of 3.0 ± 0.4 Pa.s.