80 Handbook of herbs and spices
An HACCP system should be implemented by a multidisciplinary team, including
the top management. It is specially designed for food safety and very effective if
implemented properly (Varman and Evans 1991).
On 1 September 2005 the International Standards Organization published a single
standard to encompass all the needs of the market place and designated it as ISO
- This standard ensures a safe food supply chain worldwide (Anon. 2005).
4.5 Decontamination techniques..........................................................
Decontamination or cleaning is very important in the production of herbs and spices
because of the large number of small farmers involved, and also because on-farm
processing is often carried out in the open air. Cleaning in a factory fitted with
modern equipment is very important to ensure that the end-product is of sufficient
quality. The foreign materials found in herbs and spices supplied by farmers are
surprisingly varied, and include sand, stones, dust, nails, bailing wire, pieces of jute,
cotton threads, nuts, bolts, cigarette stubs and packs, pieces of charcoal, toys, rodent
droppings, and dead and live insects.
Cleaning equipment must take into consideration the size, shape and density of the
herbs or spices to be cleaned. Most often, the cleaning process is based on shape and
density. If the shape and density of the foreign materials are similar to those of the
product, it is very difficult to remove them. It is impossible to separate out all foreign
materials completely with the technology and equipment available; hence there are
permitted levels of foreign materials and/or contaminants which will not adversely
affect the desired quality or create a health hazard. The equipment commonly used
for removing foreign materials includes magnets, sifters, air tables, de-stoners, air
separators, indent separators and spiral gravity separators. Cleaning operations are
expensive considering the cost of equipment and labour, and the likely loss of the
product during the operation.
4.5.1 Magnets
Magnets remove iron particles and pieces of metal. The cleaning machinery should
have magnets at as many points as possible. In addition to removing metals, magnets
help protect grinding equipment from damage. There are different kinds of magnets,
typically in bar and plate forms, but none are 100% efficient. Since the iron particles
are removed only if they come into contact with the magnet, the flow of the product
past the magnet should not be too dense. The magnets must also be cleaned periodically,
according to a schedule designed around the quality requirement. It should be noted
that even well-designed magnets can attract and hold only a limited quantity of
metal. A system that allows the product to flow over two or three magnets is much
more effective than using a single magnet.
4.5.2 Sifters
Sifters remove particles of the wrong size from the product via a set of vibrating
screens. The sifting operation is not totally efficient as the products are not uniformly
round or spherical, some may be oval in shape and occasionally pieces of leaves are
admixed with them. In such situations, the sifting operation becomes very difficult
and does not clean the product effectively.