Spice processing
Practical Action
Grading
Spices can be graded by size, density, colour, shape and flavour. Machines are available for
larger scale production units.
Spice
Mace
Nutmeg, cloves
Turmeric, coriander
Cinnamon
Pepper, pimento, chillies, ginger
Cardamom
Maximum final moisture content
(% wet basis)
6.0
8.0
9.0
11.0
12.0
13.0
Table 1: Spice moisture content
Grinding
Spices can either be sold whole or ground into powder. Grinding can add value to the product,
but it can also detract from the quality of the product. Many consumers are wary of ground
spices since they are frequently contaminated or adulterated. There is no easy way to determine
whether ground spices are pure or have been adulterated. In general, ground spices are made by
grinding inferior and broken spices. Also, ground spice has a much shorter shelf life than the
whole spice. Once it is ground, the flavour and aroma of spice soon deteriorate. It is better for
the small-scale processor to sell whole spices. This also removes the need for moisture proof
packaging materials and sealing machines.
For small-scale production (up to 100kg/day) manual grinders are adequate. Small Chinese or
Indian models designed for domestic spice grinding are suitable. A treadle or bicycle could be
attached to make the work easier.
For larger scale production a small, powered grinding mill is needed and models are available
that can grind 25kg/hour. A grinding mill needs to be placed in a separate and well ventilated
room because of the dust. Great care is needed to ensure uniform sized pieces/powders after
grinding and also to prevent heating of spices during grinding.
Packaging and storage
After drying, the material should be packed quickly into clean heavy gauge polypropylene sacks
to avoid any moisture pick up. The spices must be cool before they are packed into the sacks
and they must be stored out of direct sunlight to prevent condensation forming on the inside of
the sack. Workers should not directly handle the spices, but should use clean gloves and scoops.
Sacks should be labelled and dated.
The packaging requirements depend on: 1) the type of spice, 2) whether it is ground or intact
and 3) the humidity of storage. Most intact spices will store adequately in sacks/boxes if the
humidity of the air is not too high. Ground spices can also be stored without special packaging if
humidity is low but over long periods there is a loss of flavour and risk of contamination and
spoilage.
It is therefore better to store spices in a barrier film such as polypropylene (essential in areas of
high humidity) to provide an attractive package, retain spice quality and prevent contamination
and losses. If polypropylene is not available, cellulose film is adequate if it is heat sealable.
Polythene is a poor substitute and should only be used for short term storage as it allows the
flavour/aroma of the spices to escape.
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