COCOA QUALITY CONTROL

COCOA QUALITY CONTROL
By BOATENG, D. O.
BUNSO COCOA COLLEGE, COCOBOD
E.mail-polonium90@yahoo.com         Phone +233(0)240296835
Blog Website: ostracoderm90.blogspot.com

INTRODUCTION

• The importance of a consistently high standard of quality in cocoa beans cannot be over emphasized since chocolate is very competitive on the markets.
•  If the quality of the beans is poor, final product suffers and the industry as a whole looses, as consumers turn to other snacks foods.
• Throughout the food industry, and with most of the other methods of cocoa production, quality control is changing from inspection to the application of Good Agricultural Practices (GAP)
• High quality of its cocoa, ‘Ghana Cocoa’ is the standard mark for the grading of   the quality of raw cocoa beans from all producing countries. 
•  Ghana Cocoa Board is determined to maintain quality of every exportable crop under its schedule.
• ¢ The subsidiary of the Board which is responsible for preserving quality of exportable cocoa is the Quality Control Division now Quality Control Company.
• ¢ The Board insists on cocoa always being of the highest quality.  There are at present, three grades, namely grades I, II and sub-grade.

COCOA INSPECTION VERIFICATION INCLUDES:

Prior to cocoa cargo loading and stuffing:

1.      Determination of the condition of the cocoa and cocoa packaging.

2.      Determination of individual cocoa package weight by random basis.

3.      Ensure cocoa storage containers are clean and dry, ready and fit for intended cocoa cargo.

During cocoa bag loading and stuffing:

1.      Inspectors count and tally each cocoa cargo bag loaded and check condition.

2.      After completion of cocoa bag stuffing, storage doors are closed; fumigation      

Inventory Inspection made during quality control checking

o   Loading and discharge inspection.

o   Cocoa weight and quantity verification.

o   Inspection of loading, discharge and storage facilities.

o   Representative sampling for lab tests.

o   Certification of quantity and quality

o   Truck inspection.

o   Cocoa warehouse and stock monitoring.

Testing purity in cocoa beans

It is important that cocoa products especially chocolate shall be pure and wholesome.

It follows that cocoa bean which plays a good factor shall not contain any impurities which could be injurious to the health of the consumer.

The principal sources of impurity are:

1. Pesticides Residues
2. Microorganisms
3. Insects Infestation
4. Foreign Matters
5. Heavy Metals

Pesticides residue

The use of pesticides on cocoa trees and in cocoa beans stored can be lead to the presence of residue in the dried beans.

Chocolate manufacturers require that their supplies of cocoa beans comply with these limits and will monitor closely the level of pesticides on all cocoa raw materials.

Some the chemical that Quality Control Check for are:

o   Detia gas

o   Termidor

o   ULV

Micro-organisms

Excessive microbial contamination can results from too slow or inadequate drying, storage of wet beans, contamination of stored beans by birds and rodents or during drying by domestic birds and animals

Some of the microorganisms that they check for are;

o   Aflatoxins

o   Ochratoxins

Insect infestation

Cocoa beans frequently become infested at origin by several species of insects.

If not controlled by effective pre-shipment fumigation, the infestation will spread to cocoa stores which will destroy finished goods.

Chemical Used for Fumigation is Phosphine

Some of the pests are;

o   Tropical warehouse moth-Ephestia cautella

o   Cigarette beetle-Lasioderma serricone

o   Corn sap beetle-Carpophilus dimidiatus

o   Rusty grain beetle-Cryptolestes ferrugineus

o   Coffee bean weevil-Araeocerus fasciculatus

o   Red flour beetles-Tribolium castaneum

o   Rodent-Rattus spp

Foreign matters

The presence of foreign matters such as pieces of pod husk, placenta, stone, broken wood in bulk cocoa may contaminate the product, affect the flavor or cause damage to plants or machinery  apart from reducing the proportion of edible material. 

Heavy metals

These happen when acidic soil is used for cultivation. Smoke can also cause remains of heavy metals.

Some of the metals they check are;

o   Lead

o   Cadmium

o   Arsenic

MOISTURE CONTENT

Manufacturers require cocoa beans to have moisture content of 6 – 7%.  Over 8%, the beans become mouldy and below 5% they are brittle. 

This is done with a machine called the aqua boy.

GRADING

Cacao beans are graded, according to the proportion of defective beans determined by the method of test specification.

GRADE TYPES

GRADE I:       Cocoa which is thoroughly dry, free from foreign matter, smoky beans and any evidence of adulteration, and which contains not more than 3% by count of mouldy beans, not more than 3% by count of slaty beans, and not more than 3% by count of all other defects.

GRADE II:      Cocoa which is thoroughly dry, free from foreign matter, smoky beans and evidence of adulteration, and which contains not more than 4% by count of mouldy beans, not more than 8% by count of slaty beans, and not more than 6% by count of all other defects.

SUB GRADE:            Cocoa which fails to reach the standard of Grade II.  This is not purchased by the Board.  Only grades I and II cocoa are purchased at the full price.

The table below describes grade standards

	Mouldy	Slaty	Insect Damage, Germinated, flat
Grade I	3%	3%	3%
Grade II	4%	8%	6%

Mouldy Cocoa Beans:

Mouldy beans have been described as the worst defect of cocoa beans.  The most important effect of mould is on flavour.  The unpleasant flavours produced by mouldy cannot be removed by normal manufacturing processes.

The other effects of mould are:

• To increase freely fatty acid content of the cocoa butter.

• The growth of some moulds may produce mycotoxins.

Slaty Cocoa Beans:

Slaty or unfermented beans are a major defect because they cannot be made into chocolates. The production of chocolate flavour depends on the two processes of fermentation and roasting one process without the other will not improve chocolate flavour.

DEFECTIVE BEANS

Mouldy Bean:    A bean on the internal parts of which mould is visible to the NAKED                              eye.

Slaty Bean:            A bean which shows a grey or purple colour over half or more of   the surface exposed.

Insect Damage Bean:    Beans that have internal parts of which contains insects at any stage   of development, or have been attacked by insects which have caused damage visible to the naked eye.

Germinated Bean:              A bean in which the shell of which has been pierced, slit or broken by the growth of the seed germ.

Flat Bean:            A bean of which the two cotyledons are so thin that it is not possible to obtain a cotyledon surface by cutting.

Smoky Bean:       A bean which has a smoky smell or taste or which shows signs of contamination by smoke.

Broken Bean:     A beans in which a fragment is missing, the missing part being equivalent to less than half the bean.

Fragment:               A piece of bean equal to or less than half the original bean.

Piece of shell:          Part of the shell without any of the kernel

Foreign matter:     Any substance other than cocoa such as cotyledon, wood, stones etc

Waste:                    Cocoa beans shall not contain flat beans, fragments, piece of shell, dried placenta and dried pulps

GOOD QUALITY CONTROL MEASURES

At the pre harvest level

•  Climatic conditions such as rainfall can affect pod development which may lead small bean sizes.
• Ambient temperature, Evidence from Brazil indicates that the cocoa butter from beans which develop during cooler months contains more unsaturated fatty acids and it is therefore softer.
• Check planting materials, go for the hybrid which is a cross of the Amazon, these once are known to produce bulk cocoa as compared to the rest. They are also disease tolerant and high yielding.
• The types of pesticides to use, these are those that will not leave residue in the tree affecting the pods.
• The time of harvest can also affect bean quality; this should be done at interval of 1-2 weeks.
• After harvesting pod, it should not be left for a long period before breaking, this bring about germinated once which can reduce quality.
• Use wooden baton to open pods instead of machete, mechanical damage.

At the post harvest level

• Deep box fermentation, multiple turning and too much rapid drying can lead to excessive acid taste.
• Lack of fermentation can also lead to excessive bitterness and astringency.
• Do not dry for more than the fermentation period unless necessary.
• Preventing moulds;

o   Check prolonged fermentation.

o   Adequate drying.

o   Don’t store under high humid conditions.

• Do not dry in smoky environment.
• Do not store in warehouse closer to smoke.
• Store in a clean dry environment well stacked on pallets.
• Check the pesticides for controlling insect infestation to prevent residue in the beans.

Summary of quality requirement

Cocoa Beans Shall –

•  Be properly fermented and dried whole seed of tree botanically known as "Theobroma cacao linnaeus
• Be reasonably uniform in size and shape
• Be reasonably free from broken beans, fragments and small pieces
• Be free from foreign matter   
• Be free from beans of abnormal odour or flavor
• Be free from admixture of any other seeds and impurities
• The dried beans should have a moisture content of 6 – 7%.  Over 8% the beans become mouldy and below 5% they are brittle. 
• Be conform to the provisions under Rules 57, 57A and 65 of the Prevention of Food Adulteration rules, 1955 in respect of metallic contamination, crop contaminants and pesticide residue 

Source: Quality Control Company, COCOBOD, GHANA