Development of coconut based chocolate by 3D printing technology

Abstract

Chocolate is one of the chief ingredients in the global confectionary market. It contains high concentrations of refined sugar and saturated fat content. Chocolate and cocoa (Theobroma cacao) provides health benefits to cure cardiovascular disease, metabolic syndrome, neurodegenerative diseases and other chronic health conditions. Coconut (Cocos nucifera) is a very versatile and indispensable food item that is considered a complete food source, rich in calories, vitamins and minerals. Coconut kernel contains 7- 10% dietary fiber and 5% proteins, in addition to 34-60% oil content. The dietary fiber constitutes significant hypo-cholesterolemic effect. The deficiency of complex carbohydrates like dietary fiber is a matter of concern that poses major health issues causing chronic diseases such as cardiovascular diseases, obesity, colon cancer, hypertension and diabetes mellitus. The recommended acceptable intake of dietary fiber is 28.8 g/day for adults, but the actual intake was found to be lower than this limit. The present study envisages the development of chocolate enriched with coconut dietary fiber using the advanced technology of 3D food printing. Three-dimensional (3D) printing is a novel food preparation concept based on the additive manufacturing (AM) technique. The technology offers features like personalized nutrition, taking into consideration of the age, health and diet of the consumer and also customized designing of foods based on individual preferences. The study focused on the applicability of 3D printing for dietary fiber enrichment of chocolate. A 3D model of ‘gear’ with dimensions 41.50 mm × 41.50 mm × 10.00 mm was considered to study the 3D food printing. The treatment combinations for the formulation of supply material and experimental design for optimization of process parameters were done using Central Composite Design (CCD) and Box-Behnken Design (BBD) of Response Surface Methodology (RSM) respectively. Based on the analysis, the supply material composition with 9% coconut meal, 3% sugar, 0.3% soya lecithin and 87.7% dark compound chocolate was optimized. 3D food 112 printing process parameters such as extruder motor speed, nozzle diameter, conveying air pressure and printing speed were considered as independent variables. The printing parameters have significant effect on extrusion rate, printing rate, weight, thickness and hardness of the printed products. The results showed that diameter, colour, moisture content, cohesiveness and adhesiveness of the printed products were not significantly affected by the printing process parameters (p>0.05). Based on these results, the optimized condition for printing of coconut based chocolate was 0.8 mm nozzle diameter, 60 mm/s printing speeds, 2 bar conveying air pressure and 30 rpm motor speed. Nutritional analysis showed that the developed product have 8% of dietary fiber along with 54.35% carbohydrates, 32.26% fat and 4.54% protein content providing an energy value of 549 k Cal/100.g.