About Cashew Processing - Overview
The cashew 'nut' is outside of the fruit, and this makes it different from other tree nuts.
The cashew apple is an edible artificial fruit, joined to the externally born nut by a stem. The main marketable product of the cashew tree is the nut. Starting from collecting at farm level to machinery processing at factory level, and concludes with storage and transportation.
In its unrefined state, the shell of the nut is gristly and tough. Its sponge-like interior is surrounded with the thick vesicant oil, CNSL (Cashew Nut Shell Liquid).
CNSL is an important industrial raw material for resin manufacture and the shells can be burned to provide heat for the decorticating operation.
The kernels are the most important constituent of cashew nuts and they have value as confectionery nuts. A thin testa, layer of skin surrounds the kernel, separating it from the indoors of the shell.
However, it is essential that a suitable and safe cashew processing method must be followed to preserve the quality of harvested nuts against natural and man-made contaminations.
All cashew nut need to go through the following process which has to be carried out in a consistent manner.
Hence we have designed the architecture of our cashew processing machines in such a manner that each process is carried out in a perfect manner to give you the best selling cashew nuts.
- Cleaning- All newborn nuts consist of foreign matters which can be eradicated by a cleaning process. Thus the unwanted/ foreign matters will not be present during the roasting operation.
- Roasting- The process of heat sent to the cashew nut discharges the nut shell liquid and makes the shell brittle which further results the extraction of the kernel to break open the shell.
- Shelling -The shelling of cashews by machinery process results to produce clean, whole kernels free of cracks. The 'hot oil' method is the most successful mechanical shellers work on nuts. Centrifugal shellers use a system wherein, a rotary paddle projects the shells against the solid casing and the impact cracks open the shell causing no harm to the kernel.
- Pre-Grading - Pre-grading is followed to wholly reduce the final grading work and can be conducted before or after drying the kernels. For large-scale processors pre-grading can be done mechanically, separating mainly the whole from the broken kernels and sometimes separating the different size group of whole kernels.
- Drying - The kernels after they are removed from the shells have to be dried in order to loosen the red skin attached to the kernel for easy peeling.
- Peeling - Once the kernels are dried, it gets simpler to conduct the peeling machinery process. The testa is loosely attached to the kernel, although a small amount of kernels may have already lost the testa during the previous operations. The mechanized processes of peeling differ widely. They include air-blasting, suction, a freezing operation and a system of rubber rollers.
- Grading - The grading method is conducted wisely as it is the last opportunity for quality control on the kernels. Power driven rotary sieves are one mechanical method, another being two outwardly rotating rubber rollers aligned at a diverging angle.
- Re-humidification - It is important that the moisture content of kernels rise from 3% up to around 5%. This is results in making the kernels less fragile, thus reducing the risk of breakage during transport. After the process of re-humidification, the kernels can be sent for packing.
- Packing - Air-tight tins of 25lbs in weight is supposed to be one of the normal packaging for export of kernels. The packing machinery process needs to maintain a resistant level as cashew kernels are subject to rancidity and go stale very quickly. After filling and weighing, the cap should be soldered on in preparation for the 'vita pack' process.
For each of the above mentioned step we have a cashew processing machine which will do your entire task in a controlled and efficient manner. Click here more details on our cashew processing machines.
