A set of soyamilk machine was designed. Some factors were taken into consideration in order to design the machines. The design parameters considered were feed rate, power requirement, shaft speed of the blander and hopper capacity etc. Small type prototype of blender was targeted to develop with locally available stainless-steel material and single phase electric motor which will be easily functional by the progressive farmers and small entrepreneurs during 2018-19. A pasteurizing heater is an important part which was design as well as blender part. The soya poneer press was developed during 2019-20. The schematic views of the model of the blender and the pasteurizing heater.
Machine components:
A mini plant was constructed using stainless steel materials and it is made of the following components:
i) Blending unit: This unit is made up of the following sub-component parts: outer casing, hopper,
delivery tube, blending chamber, blending blade, shaft, pulley, V-belt and 0.25hp electric motor. ii) Pasteurization unit: This unit is made up of the following sub-component parts: inner casing, outer casing (water jacket), milk inlet and outlet valves, water inlet and draining valves, external casing. A blender and a pasteurizing unit was designed and developed for making soymilk. The specification of the blender and pasteurizing unit of the soymilk maker. The blender unit was operated with 0.20 kW electric motor having 6000 rpm operating speed. The blender was designed for continuous feeding and operation. Two liter per batch could feed. The weight of the blender unit was 16.26 Kg. The pasteurizing unit prepared with two cylinders. The inner cylinder was to keep the soymilk and outer cylinder was to keep the hot water. Capacity of the inner cylinder is 6 liters. The space between the cylinders was filled with water which was heated with a 2000 watt heater. The temperature of the water was monitored with a sensor (200±1 0C) which was connected with a control box. iii) Soy poneer press: This unit was design and developed during 2019-20 with Stainless Steel. Poneer press was made with round cylinder with 1.6 mm thick sheet with 5 mm SS Plate, 25 mm threaded shaft and other parts in SS. This will require less maintenance. Operation of the unit is easy to give more pressure upon soy poneer. This machine has the inbuilt container. It is amazing product and have capacity for making poneer in large quantity in the hygienic conditions along with retaining its quality.
Mode of operations of the machine for soy milk:
The blending blade was fixed on the vertical shaft inside the blending chamber. Soaked and dehulled grain of Soyabean was feed inside the blending chamber. Water was also feed with bean. The power source was then switched on for blending operation. The milk outlet valve was opened for out flow of extracted milk to the pasteurization chamber from the blending machine. This is the raw soyamilk. The water tank was then mounted on the pasteurizing heating machine. The boiling tank was filled with water to the required level. The milk was fed into the machine through the hopper. The temperature of the water was monitored through the temperature gauge. The hot water was hold inside the pasteurizer for the required time. The pasteurizer outlet valve was open for outflow of the milk. The water jacket outlet valve was open for draining of the used water. Performance test of the soya milk was done at FMP Engineering Divisional workshop, Gazipur.
Preparation of Soybean Milk:
The soymilk was as follow: the whole soybeans were washed and soaked in water (1:3) at room temperature (20±5°C) for 10 hours in normal water and husk was separated from the bean by pressing the bean followed by washing with water. The beans were then ground in blender for various time. The ratio of beans to water was 1:5 (w/v). The resulted suspension was filtered. And then the suspension insert in pasteurization unit. The outer temperature was more than 100°C and inner temperature was 100°C. The liquid was kept for 20 minutes. Hot suspension was come out by outlet. This suspension was cooled and become soymilk.
Preparation of Soya poneer:
After preparing soymilk, when the soybean milk's temperature come to 70-80 degree, the citric acid was added with soymilk and stir 1-2 times. Stir the milk with limited break not continuously. Within 15-20 minutes the milk started coagulate and water separated from it. If the milk has not yet been fully coagulated, then some more citric solution have to pour it. The coagulated milk was separated instantly, else the tofu will not get soft. Once the milk and the water separates, a clean cloth spread over a strainer and pour the milk over it. Tofu were collected on the cloth and the water was strain down into the bowl when press with the soya poneer press device. Good quality soft tofu were found after press and waiting 30-40 minutes. The tofu inside the cloth was freeze inside the cloth that can be used to make different dishes. Then prepared soya poneer was evaluated by sensory evaluation. Ten panelists were evaluated soya poneer.