Effect of coconut products, mesquite flour and stevia on the thermal and quality properties of dark chocolate

Abstract

Introduction. The present study aimed to investigate the effect of coconut products and mesquite flour on the thermal properties of dark chocolate with stevia. Materials and methods. Сocoa butter, cocoa mass, stevia, coconut flour, mesquite powder, and coconut butter are used for the preparation of dark chocolate. Chocolate samples were prepared according to a classic technology. The determination of the energy value of the dark chocolate samples was performed through AOAC procedures. A differential scanning calorimeter was used for the determination of the melting points of the chocolate samples. Results and discussion. An increase in the mass concentration of functional ingredients leads to an increase in the proteins, fats and a decrease in the carbohydrate content and lipid content. Lower concentrations of carbohydrates were identified in chocolate 1 (38.11%) and chocolate 2 (45.50%). From a statistical point of view (p<0.05) it can be stated that there are notable differences between the concentration of carbohydrates in chocolate with stevia 0.01% and that of chocolate with stevia 0.03%. These differences can be explained by the higher carbohydrate content of coconut flour. Sweetener type and functional ingredients did not change the melting properties of the dark chocolate samples significantly (p>0.05). However, low melting temperatures around 27–35 °C implied that thus low-melting polymorphic forms occurred during the production of the samples. For stevia including dark chocolates, onset temperature (Tonset), peak temperature (Tpeak) and end temperature (Tend) values were found between 25.01–28.57 °C, 33.95–34.64 °C, and 38.69–38.01 °C. Concerning the ΔH parameter, it varied from 32.60 to 33.06 J/g. Samples with functional ingredients have significantly higher values for the antioxidant capacity indicator 97.21μmol TE/g d.m. – 112.62μmol TE/g d.m. Conclusion. Results of melting profile, and nutritional and antioxidant properties showed that the quality attributes of the chocolates with stevia were substantially affected by the ratio of the functional ingredients (mesquite flour and coconut products).