A CONCHING CUM TEMPERING MACHINE FOR CHOCOLATE PRODUCTION

Abstract

Chocolate industries are fully dominated by multinational companies. There are several homemade chocolate units producing chocolate on a smaller scale. Consumers prefer branded chocolates over homemade chocolates because of their quality and texture. For obtaining good textured chocolate, the chocolate mix should be conched and tempered correctly. However, in case of homemade chocolate units run by Self-help Group (SHG), there is a lack of conching cum tempering machines at affordable prices. A small capacity conching cum tempering machine at affordable price would improve the quality of chocolate. Hence, in this study, an attempt has been made to develop a conching cum tempering machine for chocolate production, which is suitable for homemade chocolate units. The developed conching cum tempering machine consists of jacketed chamber with stone base, stone rollers and spring loaded scraper assembly, refrigeration system, motor and gear box, Variable Frequency Drive (VFD), water tank and water pump, control panel and vibration platform. The process variables used in the study were conching temperature (60,70 and 80°C), conching time (11, 14 and 17 h) and speed of rotation (60, 75 and 90 rpm). The optimisation of conching process parameters was analysed using RSM based on the quality characteristics of the conched chocolate mix. The optimum conditions of conching process namely, conching temperature, conching time and speed of rotation were found to be 70°C, 14 h and 75 rpm, respectively. The tempering process variables used in the study were tempering temperature (27,29 and 31°C), tempering time (120, 150 and 180min) and speed of rotation (40,60 and 75 rpm). The optimum conditions of tempering process namely, tempering temperature, tempering time and speed of rotation was found to be 29°C, 180 min and 60 rpm, respectively. The physicochemical properties of chocolate produced at optimized conching cum tempering process such as fat, protein, total sugar, carbohydrates, free fatty acid and energy value were estimated as 33.74 g/100g, 6.32 g/100g, 44.83 g/100g, 56.77 g/100g, 1.30 % and 556.02 kcal, respectively. The capacity of conching cum tempering machine was found to be 10 kg/ batch and the energy consumption was 17.7 kWh for optimized conching cum tempering condition. The benefit cost ratio of machine was found to be 1.87:1 with payback period of 2.5 years.