This measuring Method enables to find Plastic Viscosity and Yield Value on chocolate samples at 40°C, according OICC standard.
Pre-shearing of 15 minutes of the sample at 40°C including in the C or DIN11 cup, installed into the Peltier Air-Air temperature control unit; this system don’t use water or liquid circulation, just ambient air.
The OICC 1973 standard advice to realize a Step by Step ramp from 5 to 50s-1 at 40°C +/- 0.1°C.
The reached curve is then fitted with CASSON or CHOCOLATE model, in order to calculate the following parameters: Yield Value in Pa and Plastic Viscosity in Pa.s that are the characteristics of plastic shear-thinning fluids, with yield value.
Example of measurement on milk chocolate:
T °C = 39,9 °C
Yield Value = 9,3 Pa
Plastic Viscosity (CASSON) = 1,42 Pa.s
Correlation factor: R = 1,000