DEVELOPMENT AND PERFORMANCE EVALUATION OF UTM OPERATED COCOA BUTTER EXTRACTOR

Abstract

Cocoa (Theobroma cacao L.) is a commercial plantation crop in India. It is the main raw material in the production of chocolates, cosmetics, health drinks, pharmaceuticals etc. Cocoa beans, the seeds of cocoa tree are processed to obtain chocolate liquor, cocoa butter and cocoa powder which are the main ingredients of chocolate and a vast range of products like cocoa beverages, ice cream and bakery products and impart a characteristic and distinctive flavour to its derived products. In addition to its confectionary use, cocoa also has cosmetic and pharmaceutical applications. The cocoa beans which are embedded in a mucilaginous pulp inside the pod consists of two parts- seed coat (shell) and seed cotyledon (nib). Shell is removed from the cocoa bean before or after the seeds is roasted. After roasting the nibs are grinded and the butter is extracted. Cocoa butter extraction is one of the critical steps in the processing of chocolate that is derived from cocoa beans. It affects the quality of the chocolate in terms of flavour and purity. The suitable extraction method is needed to produce high quality and quantity of cocoa butter and other bioactive compounds. Latest extraction techniques suitable for cocoa butter extraction are ultrasound-assisted extraction (USE), pressurized liquid extraction, microwave extraction and supercritical fluid extraction. The use of these methods of extraction is less favourable and cost required is even greater. Hydraulic press is the popular method to extract cocoa butter from cocoa mass. The present study focuses on the development of a Universal Testing Machine operated cocoa butter extractor and the performance of the developed cocoa butter extractor was evaluated in terms of yield of cocoa butter, time of butter extraction, and extraction efficiency. The developed machine consists of universal testing machine, piston, filter press bag, cylinder and collecting plate. Well ground cocoa mass stored at refrigerated condition was double boiled to a temperature of 42 °C to melt it into a semi liquid form. 2 kg of cocoa mass was poured into the filter press bag and the bag was tied up. Filter press bag was kept in the cylinder and the piston was set up above the filter cloth. Filter bag along with the cylinder was then placed on the collecting plate. This attachment was mounted to the loading section of the Universal Testing Machine and switch on the machine. By adjusting the load indicator, force was made to desired value (kN) in the dial gauge. To apply the load on the piston, the valve in the control panel was opened and start button was pressed. The pressure excreted by the Universal Testing 55Machine on the piston compressed the filter bag containing cocoa mass. Thus, the movable middle cross head descends along the screw column and compressed the piston to extract the cocoa butter. The extracted cocoa butter was then collected in collecting plate placed below the cylinder and taken out through the outlet. The performance evaluation of the machine was done in terms of extraction efficiency, cocoa butter yield and time of extraction. It was observed that the maximum extraction efficiency of 85.37 % was obtained at 15 kN compression force. The maximum yield obtained and time of extraction was found to be 916.87 g and 10 minutes, respectively.