Module I - Plantation Crops

Module I

Plantation Crops

E .P. Banuu PriyaAssistant Professor

Kongu Engineering College

Importance of plantation crops

• Plantation crops are high value commercial crops

• Economic importance

• Export potential

• Employment generation (app. 0.5 million people)

• Poverty alleviation (rural sector)

• Ministry of Agriculture - Coconut, cashewnut, cocoa, arecanut, oil

palm and palmyrah

• Ministry of commerce - Tea, coffee and rubber

Cashew nut

• Cashew is brought from Brazil to India by the Portuguese • Initially cultivated to arrest soil erosion and sea winds

• India was the first country to enter the global cashew trade.

• The country processes about 1.18 million tonnes of cashew

• 1959 – 150 mills; 2008 – 3500 mills

• Organized - 46 % ; Unorganized – 54 %

• Annual demand - 1.5 million tonnes, only a half of which is met by the

existing production.

Cashew (Anacardium occidentale L.)

• India is the largest Producer, Processor and Exporter in the world ?

1960 1970 1980 1990 2000 until 20120

200000

400000

600000

800000

1000000

1200000

Top production - cashew nut

Mozambique Nigeria Vietnam India

Cash

ew P

rodu

ction

(MT)

Contd..

• India imports - raw in-shell cashew from Congo, Tanzania, Indonesia and

Thailand (Zheng, 2012)

• India exports processed nuts to USA, UK, Japan, Netherlands, Australia,

Canada and Germany (Directorate-General of Commercial Intelligence and

Statistics, 2011).

• “zero cholesterol nut”

Nutrition Composition

Protein - 21.2

Carbohydrates - 22.0

Fat - 47.0

Rest is total Minerals (Calcium, Phosphorus, Iron), Moisture and total Fiber

(in 100 g of cashew nut)

Parts of cashew fruit

Ripening stages of cashew

Processing of cashew• Raw material

• Cleaning• Grading• Drying • Storage

• Conditioning• Roasting or steam cooking• Decortication (wooden mallets or cutting)• Separation of kernel• Kernel drying• Peeling• Grading and packaging

Over view of processing

Raw cashew nutsFreshly harvested cashew

nuts (initial m.c. 25%)

Cleaning (Rotary screen)

Grading

Sun drying

(2-3 days till 8-9% m.c)

Storage (gunny bags – 8-9 %)

Methods of processing

Cleaning

• Manual cleaning – sand, stones, dried cashew etc., are removed• Hand sieves (0.95 cm mesh)

Conditioning• Washed by dipping the nuts in cold water in a tank

• Heaped on the floor are covered with moist gunny bags

• Water is sprinkled over the heaps periodically to keep the nuts in wet condition and

allowed to absorb moisture gradually

• Conditioning with moisture ensures quality of the final product

• Over humidification – desert grades

• Under humidification – scorched grades

• Steam cooking/roasting

• Oil recovery will be less and breakage of kernels would be more if the nut has not

absorbed sufficient amount of water

Roasting

Purpose - carefully separate the kernel without CNSL contamination - less breakage

• Open pan• Drum drying (unconditioned)• Oil bath roasting

Open pan roasting

• Used by traditional cashew processors in India.

• This technique is very simple with minimal equipment requirements.

• Requires skill and judgement in order to prevent the nuts from burning.

• The roasting pan is an open circular mild steel dish, measuring 2 to 2.5 feet in

diameter, supported over an open fire.

• Between 1 and 1.5 kg of raw nuts are placed on to the heated pan at a time.

• The nuts are heated on the pan, with constant stirring, in order to prevent burning

• As the nuts heat up, the CNSL is exuded onto the pan

Open pan roasting

Drum roasting• An improvement on the open pan roaster was the development of a drum

roaster, within which the cashew nuts are roasted.

• Nuts without any conditioning are fed into a rotating drum, heated initially to red hot to allow the shell of the nut to ignite and burn

• Drum is tilted at an angle (15-20°) over the fire and rotated during heating to prevent the nuts from burning

• During rotation, nuts pass through the cylinder and out of the opposite end of the drum.

• Duration of the roasting process can be regulated by changing the speed of rotation of the drum.

• Takes about 3-5 minutes and the drum is rotated by hand

• Rate of shelling and out turn of whole kernel is higher

• Cylinder is covered in a hood connected to a chimney which draws the black smoke upward into the atmosphere and makes it less unpleasant for the operator

Drum roaster fired from a furnace below

Oil bath roasting• Consists of a rectangular vessel and embedded in brick work and

heated by a furnace – shell is used as fuel• Conditioned nuts are passed through a bath of heated cashew nut

shell liquid (CNSL) maintained at a temperature of 175-220°C (190°C) for about 1-2 minutes

• Small (18 – 22 cm) -90 sec• Medium (23 – 25 mm) – 100 sec• Large (26 – 35 mm) – 110 sec

• Screw or belt conveyor is operating inside the bath of liquid• Roasting time is adjusted by the speed of the conveyor• During the passage, the shell gets heated , rupturing the cell walls

and releasing the shell liquid• Nuts are conveyed through a suitable outlet to a centrifuge – residual

oil is removed • Oil recovered from the roaster and centrifuge is filled into drums.

Mild roasting• Conditioned grains are mild roasted for 20-25 min to remove

surface water• Loosens the kernel from the shell • After roasting, the nuts are spread on the floor as a thin layer for

cooling and later sent for shelling

Shelling

• Roasted nuts are placed on a flat surface and cracked with a wooden mallet

• Efficiency - 10 nuts/min• 8 h shift - approximately 30 kg of raw nuts – 7.5 kg kernel• Cooling – 2-4 h

Kernel drying – “BORMA”

• Purpose – to peel the testa from the kernel• Temperature – 60-70°C• Time – 6-7 h• Final m.c – 3.5 – 4%• Borma ovens are fired – shell or CNSL removed cake • Natural draft stack – 13-15 cm • Cooling

Borma or Tray dryer

Peeling

• The peeling process involved removal of testa from the kernel with the help of sharp knife (made of bamboo).

Rehumidification

• Exposed to humid air• m.c – 5 %

Grading• Grading operation is important since it is the last opportunity for

quality control of the kernels.

• Grading system is known as the American Standard, which is also incorporated in the Indian Government export criteria.

• Kernels are categorized on the basis of colour and condition.

• Peeled cashew nuts can be classified into between 11 and 24 grades. These are roughly divided into three groups: white whole, white pieces and scorched grades.

GradingS.NO GROUPS SPECIFICATION

1 White wholesW180 (super large)W210 (large)W240W280W320W450

Between 120 and 180 kernels per lb (266-395 per kg) 200 and 210 kernels per lb (395-465 per kg) 230 and 240 kernels per lb (485-530 per kg) 270 and 280 kernels per lb (575-620 per kg) 300 and 320 kernels per lb (660-706 per kg) 400 and 450 kernels per lb (880-990 per kg)

2 White piecesButtsSplits

Pieces

Small piecesBaby bits

A kernel broken cleanly across the section of the nut.Kernel which has broken down the natural line of cleavage to form a cotyledon.

A kernel which has broken across the section but does not qualify for a butt and is above a specific size.

As above but smaller.Very small pieces of kernel which are white in colour.

3 Scorched gradesWholes

Butts

Whole kernels that have been slightly scorched during the process but are otherwise sound. These are not graded according to size.Butts that have been scorched.

Packaging

• Graded kernels are packed in square tins of 25lb capacity• After filling and weighing - 65 cm vacuum and filled with CO2

• Tins are carefully tested for leaks after a day’s storage. • Then they are packed in cartons• Flexible packages - polyethyene and polypropylene • filled with 33.3% vacuum and 66.7% CO2 (1:2 ratio of CO2:N2)

Semi - mechanical• Grading of raw nuts (before roasting)• steam roasting (instead of open pan or drum or sun or oil-bath

roasting) • cutting (instead of shelling)

Grading

• 3 groups – small, medium, large.• Depending on size, nuts may require different timings for roasting• Vibratory screens / calibrator

Steam roasting process

• The steam roasting process, commonly known as “cooking process” • Baby boiler followed by a steam cooker where the cashew nuts are

cooked with steam• Adopted widely in India

Baby boiler

• Hand stoked fire tube boiler, which produces steam at 4.5-5 kg cm−2

• 2-3 kg fuel once in 15-20 min• Cashew shell or de-oiled cake• Discharge – stack height – 13-15 cm

Cashew nut cooker

• Maximum – 360 kg cashew can be processed• Steam pressure – 4.5 – 5 kg cm−2

• process time - 10-20 min • total batch time is about 40- 45 min• cooking operation - 2-4 h in a day• 5-10 batches of nuts (depending on capacity)• Cooling

Cutting

• nut-shaped knives• nuts placed between the knifes and pushed towards kernel to cut the

shell leaving the kernel intact• 40 to 50 kg raw nut/person/8 hr• 90 % whole kernel• Nuts smaller than 18 mm cannot be cut using cutting machines

FULLY AUTOMATIC METHOD OF PROCESSING• OLTERMARE

1. Cleaning and calibration2. Washing and conditioning3. Roasting, centrifugation and cooling4. Drying5. Shelling and pneumatic separation of the shells6. Peeling, grading / sorting7. Packing

Cleaning and calibration

• size grading and pre-cleaning• dried raw cashew nut (RCN) – dust, debris etc.,• calibrator/grader machine is used, the machine will have cylinder

shaped sieves having whole of various dimensions/size • RCN passed through different wholes will be segregated and collected

separately• 3-5 grades (India only 3)

Roasting and centrifuging

• CNSL roasting followed by centrifuging to remove the remaining oil• conveyed through the cooling tunnel• next section (shelling)

Shelling

• shelling machines - shell is split into two halves• kernels and shells - vibrating screen• Aspirator – suck out empty shells• If not separated – centrifugal separator • super calibrator - whole, broken and rotten kernels are separated.

Peeling

• Mechanical and pneumatic actions – remove testa• Rocket peeler• Air peeling (pneumatic) machine

Raw nuts

Conditioning

Drum roasting

Hand shelling

Borma drying

Hand Peeling

Grading

Packing

Shells

Testa

Cashew Processing – Quilon (Kerala)

Raw nuts

Conditioning

Mild roasting

Shelling in leg & Hand operated machine Shells

Borma drying

Hand peeling

Grading

Rehumidification

Packaging

Expeller

CNSL Residue Testa

Cashew processing - Mangalore

Cashew processing - Panruti

Raw nuts

Sun Drying

Hand Shelling Shells

Borma drying

Hand peeling

Grading

Packaging

Kilns

CNSL ResidueTesta

Raw nuts

Conditioning

Single action cutting m/c

Improved Through Flow Drier

Abrasive peeler

Hand Peeling

Grading

Rehumidification

Packaging

Expeller

CNSL Residue

Shells

Peels

Extraction

Residue

Improved Cashew Nut Processing

Tannin

Storage

• Resistant to insects

• Do not suffer from infection or deterioration in quality up to six months after harvesting

• Optimum moisture contents is 8.9% for good keeping quality and for yielding good quality kernels

Mechanical sheller• Designed by Post Harvest Technology Centre, Indian Institute of

Technology,Kharagpur.

• Sheller uses principles of compression and shear, taking into account the physical and mechanical properties of cashew nuts.

• Consists of four compartments power supply transmission, feeding, shelling and discharging

• Feeding section consists of a hopper and horizontal screw conveyor for positive feed of the roasted nuts to the shelling section.

• Design criteria for the hopper and screw conveyor use size, bulk density, coefficient of friction and angle of repose of roasted cashew nuts.

• A flat plate sliding gate is used to control the feed rate of cashews into the sheller.

Contd..• Shelling of roasted nuts takes place between two wooden discs, one of which is

stationary (fixed to the machine casing) while the other is mounted on to a shaft.

• The rotating disc is spring loaded in order to compress and shear the roasted cashew nut against the stationary disc.

• Sufficient pressure is exerted by the spring in order to compress the nuts between the two discs.

• The compression and differential speed of the discs causes the shells to be broken and removed.

• At the bottom is a square opening for discharging the kernels and shells.

• A conduit is provided to prevent the kernels from being damaged by falling on to the collecting tray.

• Performance of the Sheller is optimal at 320 rpm. • Capacity :18 kg/h• Shelling efficiency :70 %• Whole kernel yield :50 %• Half split yield :22 %• Broken yield :28 %

Cashew shelling machine

Cashew products

• Three main cashew products are traded on the international market: raw nuts, cashew kernels and cashew nut shell liquid (CNSL)

• A fourth product, the cashew apple is generally processed and consumed locally.

• The raw cashew nut is the main commercial product of the cashew tree, though yields of the cashew apple are eight to ten times the weight of the raw nuts.

• Raw nuts are either exported or processed prior to export.

• Processing of the raw nuts releases the by-product CNSL that has industrial and medicinal applications.

• The skin of the nut is high in tannins and can be recovered and used in the tanning of hides.

Cashew nut shell liquid• Cashew nut processing allows for the development of an important by-product,

which can increase its added value.

• The liquid inside the shell (CNSL) represents 15 percent of the gross weight and has some attractive possible medicinal and industrial uses.

• CNSL is one of the few natural resins that is highly heat resistant and is used in braking systems and in paint manufacture.

• It contains a compound known as anacardium, which is used to treat dermatological disorders.

• The main markets for CNSL are the United States, the European Union (mainly the United Kingdom), Japan and the Republic of Korea.

• Together these account for over ninety percent of world trade, most of which is supplied by India and Brazil.

Cashew apple

Plucking and removing nuts

Washing and weighing

Fruit mill

Juice extractor

Sulphitation

Inoculation

Fermentation

Distillation

Adjusting strength to 60%

Aging in Wooden vats

Dilution to 43%

Bottling

Preparation of Feni

Cashew kernels• 60 percent of cashew kernels are consumed in the form of snacks

while the remaining 40 percent are included in confectionery.

• Cashew competes in the same market as other edible nuts including almonds, hazels, walnuts, pecans, macadamias, pistachios and peanuts.

• There has recently been a considerable rise in demand for edible nuts by consumers interested in quality and health aspects of food.

• The breakfast cereal, health food, salads and baked goods markets are all expanding markets for cashew nuts.