A study on the effects of some soy products on rheological and textural properties of milk chocolate

As the consumer expectation for healthy and functional foods is increasing, utilization of many alternative ingredients is proceeding constantly in food production nowadays. Soybean products are among these ingredients since they involve high quality proteins, isoflavones and they are free from cholesterol, lactose and gluten. Chocolate is one of the most widely consumed food products in the world and rheology of chocolate is vital for its quality and production cost. Rheological properties of chocolate are directly related to its composition, texture, the amount and time of shear rate applied and temperature. Ingredients' physical properties influence some parameters of chocolate such as color, sensory evaluation and texture. Textural properties of chocolate affected by also rheology and gives information about the quality of chocolate. In this study, the rheological properties of vegan chocolates prepared by soy milk powder (SoMP) and soy protein isolate (SPI) were investigated and compared to milk chocolates containing whole milk powder (WMP) and skimmed milk powder (SMP). Textural and sensory properties of all chocolate types were also determined. Various conching times (2, 4, 6 hours) are applied. Physical properties of powders were also determined to associate with rheological and textural properties of the chocolates. The rheological properties were measured by using a rheometer Hardness of chocolates measured by texture profile analyzer by using a three-point bend probe The best models fit to the rheological data (R 2 >0,99) were Casson, Hershel-Bulkley and Bingham models