The process of cooking the raw cashew nuts (RCN)
Next, we will continue with the explanation of our production process, and how the stages of humidification, rest, cooking and centrifugation of the raw material occur.
The basic principle of the humidification step is to replace the water in the cashew nut, making it more resistant to heat and mechanical shock. Cashew nuts with initial humidity between 5 and 12% are humidified with water in the humidification silos and remain in this process for up to 2 hours. The cashew nuts should obtain final humidity between 10 and 18%.
After the raw material is humidified, the water is removed from the silos and the cashew nuts must remain in them for 45 to 90 hours. Samples are taken from each type of cashew nut for moisture determination, before and throughout the process, and for prior release of the cashew nuts for cooking.
Inside the cooker, they pass through a conveyor belt which transports the cashew nuts to be immersed in the heated LCC (cashew nut liquid) itself. Cooking or frying is done at a temperature of 210 to 230°C for about 3 minutes, depending on the size and humidity of the cashew nuts. The purpose of this operation is to make the shell friable, vitrify the shell liquid and facilitate the release of the kernel from the endocarp. During cooking, the cashew nuts (at room temperature) suffer thermal shock when they come into contact with the high temperature of the LCC, creating a great steam pressure, followed by expulsion of water and the LCC contained.
After the cooking operation, the cashew nuts are sent to the centrifuges for the removal of the remaining LCC, and finally, the raw material falls on a vibrating sieve to remove impurities. Afterwards, they are transported to the cooling silo.
With this, one can observe the careful processes through which the raw cashew nut passes to obtain the kernel. In the next post we will continue the description of our process and to better visualize the treatment that is given to the cashew nut kernel.