Rheological properties of molten chocolate masses during storage - influence of emulsifiers
Production trend in the chocolate industry is to purchase finished cocoa liquor or finished chocolate mass which is then used in production of different chocolate products. If the finished chocolate mass is supplied to the facility, it is used within 30 days. The rheological properties of chocolate are highly important in quality determination and consumer preference. Since chocolate is a non-Newtonian fluid, its properties could be changed during the afore mentioned storage period. The aim of this research was to monitor the rheological properties of dark chocolate during 30-day storage at 50°C. Different emulsifiers (lecithin, PGPR, citric acid esters of and mono- and diglycerides of fatty acids (citrem) and citric acid esters of and mono- and diglycerides of fatty acids 2in1 (citrem 2in1)) were added to the chocolate in order to elucidate the influence of an emulsifier on the rheological properties during storage. The results showed that the rheological properties of all chocolate samples changed during storage. The addition of lecithin lowered plastic viscosity and yield value. At the end of the storage period, the yield value of the chocolate mass with lecithin increased, while other emulsifiers decreased its value.