Kakao yağının kristalleşme davranışı üzerinde kayma hızı ve soğutma hızının etkileri

Abstract

The purpose of this study was to determine the effects of shear and cooling-heating rates on the rheological behavior of cocoa butter. Three different shear rates (25, 50 and 100 s -1 ) and two different cooling rates (1 and 10 °C.min -1 ) were applied for crystallization of cocoa butter at 20, 22 and 24°C. Also, effects of shear and heating-cooling rates were monitored during the cooling and heating cycle between 70-20°C. When the cooling rate was 1 °C.min -1 , viscosity reached the highest value of 0.6 Pa.s with a shear rate of 25 s -1 . A rapid rate of cooling generally led to nucleation at a lower temperature compared to slow cooling. It was observed that crystallization of Form V was improved by shear and induction time of crystallization decreased as the rate of shear increased. The longest induction period was obtained at 24°C. Effect of cooling rate was more significant at low temperatures (P < 0.05). It was also concluded that the crystallization behavior of cocoa butter was dependent on both shear and cooling rates under isothermal conditions.