Design and Development of a Pulper for Kendu Fruit

Abstract

Kendu (Diospyros melanoxylon Roxb.) is a minor forest produce (MFP). The plant is abundantly grown in India as a source for its leaves, which is used commercially for bidi making. It is a wild fruit with high nutritional and medicinal value. The pulp of Kendu can be processed to various value-added products, like any other fruit pulp. However, manual removal of hardcover and seeds, and separation of the pulp are labor intensive and time-consuming. This problem limits the potential use of the fruit. There is a need to develop a mechanical pulper to address the issue. The fruit can be utilized to its maximum potential if proper value-addition techniques and processing facilities are developed. This work aimed at coming out with a need based low cost solution for utilizing Kendu through value-addition that can ensure food and nutritional security, and income generation for the tribal of the locality and the poorer section of the society. To achieve this, a complete package of work was taken up starting from finding various properties of the fruits, utilising those properties for design and fabrication of a pulper for the fruit, extracting the pulp using the pulper, and using the pulp for making various value-added products. The machine design, operating conditions, cost economics, and process parameters were optimised. The fabricated pulper has an overall dimension of 1.2x0.75x0.40 m and a machine throughput of 50 kg/h. The housing field area of the machine is 1.130 m2. The pulper was optimized for its machine efficiency and cost. The overall extraction efficiency of the pulper was 78.36 % at an optimized speed and feed rate of 260 rpm and 2.5 kg/min, respectively. Benefit-cost ratio (BCR) and return on investment (ROI) were 1.25 and 120.22 % respectively. The cost of extracting pulp from Kendu was ₹1.29 INR per kg of fresh fruit. The pulp so extracted by the pulper was used for making various value-added products such as nectar, jam, powder, and bar. Chemical preservatives like sodium benzoate (350 ppm) and potassium-meta bisulfate (600 ppm) were optimized for pulp preservation with maximum acceptability and microbial stability for storage of 90 days at 4 ± 1 °C. Effects of the storage conditions on microbial, sensory, and physico-chemical properties were recorded. All these properties were in the acceptable range for consumption. The designed pulping machine can thus, be a boon for processing, value-addition, and commercialization of Kendu fruit and can very well support the livelihood of tribal in the locality.