cashew process overview
cashew process was start in India 100 years ago. years ago all cashew processor had use manual cashew process in India. cashew process was born in south India. in this process want skill labor for cashew processing.in manual base cashew process all work are doing labors . after in this technology time ,cashew produces country are develop different machinery and easy technique to cashew process. right now this time have almost every cashew process work machinery in market . but cashew process machine are not given 100% performance. cashew processor are use more machine for decrease labor and production cost .Krishna industries are specialize in mfg. cashew process machinery in India.
cashew Steam roasting (Boiling):-
In conditioned nuts are steam cooked in a specially built steam cooker at about 120 to 140 ibs/sq inch pressure for 8 to 10 minutes. In this process the cashew nut shell liquid comes out and gets collected in the cooker. The oil is separately removed and cooked nuts have been air dried and shelled by hand cum leg operated machine. In this method quality white whole kernel recovery is 80 to 90 percent and the valuable oil (CNSL) is recovered completely.A general comparison of the above methods would show the oil bath method and steam roasting systems require more initial investment and higher maintenance costs, the drum roasting method being the cheapest. From the point of view of environmental pollution the safest is the steam roasting method.
After boiling 12hr to 48hr normal drying…
cashew Shelling (cutting):-
cashew nut Manual shelling:-
The nuts after roasting are shelled manually except in some units where hand-and leg operated shelling machines are used. The manual shelling is an operation which requires some amount of dexterity. The nuts are knocked 2 to 3 times on each of the long edge by wooden mallets or light hammers taking care to see that the whole kernels are released without damage or breakage as far as possible. The workers in the shelling units in cashew factories have acquired the skill through practice and the out-turn is more than 90% of the whole kernels in most of the factories. Individual workers output is about 7 to 10 kg per hour working day. As the shell oil is highly corrosive the workers smear ash or clay on their hands to prevent contact of the oil with the skin. The mechanical shelling gadget consists of two blades, between which a raw nut is inserted. The gap is adjustable and therefore, it will be advantageous if the raw nuts are pre-graded on the basis of size. By means of a lever operated by leg, the blades are brought which will cut into the shell without damaging the kernel inside. When the level is operated, the halves of the concave blades are opened which in turn opens the shell. The kernel is scooped out by means of a sharp needle. The output per worker per 8 hrs shift in this method of shelling is estimated to be 15 to 18 kg of kernel.
B.cashew nut Auto shelling:-
The Auto shelling machines of the Cashco system are also chain fed but the nuts are automatically placed in the right position. The shelling device has two knives that cut the sides of the nut and a pin that is wedged into the stalk end of the nut separates the shell halves. The advantage of this system is a fully mechanized operation with an output of about 75% whole kernel qualities. Nuts smaller than 15mm cannot be processed. Centrifugal Sheller’s use a system which is simple and enables a continuous flow. A rotary paddle projects the shells against the solid casing and the impact cracks open the shell without breaking the kernel. All sizes of nuts can be processed by this method; however, it is necessary to grade the nuts into four or so group ranges because a different rotary speed is used for the various size groups. The percentage of whole kernels produced is around 75%. By preparing the shells with grooves and weakening the strength of them before the operation begins, the percentage can be increased.
cashew kernels and shells Separating: –
After shelling, shell pieces and kernels are separated and the un shelled nuts are returned to the shelling operation. Usually blowers and shakers are used to separate the lighter shell pieces from the kernels. The greatest problem is to recover small pieces of kernel sticking to the shell. This is usually done manually from a conveyor belt used to carry all the sorted semi-shelled nuts.
cashew nut Drying:-
After the kernels are removed from the shells they have to be dried to reduce moisture and loosen the adhering testa. Most commonly sued one is Broma Drier. The chambers of the drier are indirectly heated by flue gases from a furnace at the bottom. Cashew shells are burnt as a spirce of heat. There are 4 to 6 chambers and in each chamber six-wire-mesh trays of 90 x 45 cm and 10 to 15 cm depth are loaded. Air vents are provided at the top and sides for the moisture to escape. Each tray can hold 10kg of material to a depth of 5 to 7 cm. Temperature ranging from 70 to 100 Ċ of the upper trays to 40 to 70 Ċ in the lower trays will be prevailing. In order to get uniform drying, the position of trays is changed at intervals of 10 to 30 min. The normal duration of heating is 6 to 12 hrs. During this step despite precautions excessive scorching is likely to occur. To minimize the losses, a through-flow drier has been designed and fabricated at CFTRI Mysore with a capacity of 250kg in a 4 hrs shift to work at a temperature of 80 oc . The scorching of cashew kernels is totally avoided and the drying time is reduced to 4 hrs. The moisture content of the dried samples will be in the range of 2 to 4.5%.
cashew nut Moistening:-
This process depends on moisture room or humidifier machine. Add moisture 2.5% and final moisture 5% to 6%.
Peeling is the operation of removal of the testa (seed coat) from the kernels. The skin would be loosened from the kernels by the drying which 137
Enables easy peeling off. Peeling is done by hand. Manual peeling is done by gentle rubbing with the fingers. One person can peel about 10 to 12kg of kernels per day. In a small percentage of kernels, pieces of testa may still be adhering and these are removed with the help of sharp bamboo sticks/other devices. The testa which had been hitherto wated has been found to be an excellent source of tannin.
cashew nut Grading :-
Kernels are graded according to the size manually. In the international market bold whole kernels fetch premium price. The grading standards developed in India refer to white whole (undamaged) kernels and indicate the number of kernels per lb of weight. The largest kernel come in the grade W210 (440 to 460/kg) and the smallest of the seven grades is W500 (1000 to 1100/kg). Generally, Brazilian kernels have a relatively high proportion of large wholes, with the extra attraction of the 180”s grade, known as Special Large Wholes. The white whole kernels are priced according to size. Further classification refers to broken kernels, butts, splits, pieces, small pieces and whether kernels are white of scorched. The next stage in the processing is the grading of kernels on the basis of specifications for exportable grades. There are 27 exportable grades of cashew kernels. The kernels are sorted into wholes, splits and broken primarily on the basis of the visual characteristics. The wholes are again size-graded on the basis of the number of kernels per 1 lb. the entire grading operation is done manually. However for size-grading mechanical operation is also practiced (www.cashew coca/process). The highest price is paid for better quality kernels of the W180 and W210 grades which are the largest and heaviest grades. In order to safeguard and guarantee quality, producers and exporters have introduced quality standards which must be met by cashew exporters. The ISO 6477 standard was introduced in 1988 on order to unite the Brazilian and Indian classifications and to give one single classification scheme for quality control.
cashew nut Packing: –
Final operation is packing in 10 kg capacity tins which are subsequently evacuated and filled with carbon dioxide. In some parts to overcome the possible over-drying are humidification step is introduced before packing. The practice of filling with an inert gas is mainly to combat infestation during transit. It may be pointed out that with high quality nut, free from infestation, storing with or without carbon dioxide makes very little difference particularly with reference to rancidity. The importance of inert gas appears to be more for circumventing a possible insect attack from an occasional insect egg entering the tin while packing.
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