Introduction
Cumin is a small annual herbaceous plant (Cuminum cyminum) that is a member of the parsley family (Umbelliferae). It is a native of the Eastern Mediterranean countries and Upper Egypt, but is now cultivated in Morocco, Iran, Turkey, India, China and the Americas. The seeds of the plant are used to add flavour to spicy dishes. They are also used as an appetite stimulant and to ease several stomach disorders.
This brief outlines the important steps that should be taken pre-harvest and post-harvest to ensure that the dried cumin is of top quality for the market.
Types of cumin
There are two main types of cumin:
• White cumin seeds which are the most common type.
• Black cumin seeds that are popular in Iran. The seeds of black cumin are smaller and have a sweeter aroma than the white seeds. They are sometimes confused with nigella, another seed that is used in Indian cookery. They both come from the Umbelliferae family of plants.
Cumin production
Cumin is an annual herb that grows best in sunny climates with some rainfall (over 2000mm a year). It can grow at elevations up to 1000m above sea level. The plants grow to about 25cm in height. They should be planted at intervals of about 0.75m. The small white or pink flowers grow in clusters on short stems, looking like small umbrellas.
Harvesting
The seeds are harvested about 4 months after planting when the plant begins to wither and the seeds change from dark green to a brown-yellow colour. The seed is small and boat shaped with nine ridges along the length. The seeds are harvested by removing the whole plant from the ground.
Drying
The plants are dried in the sun or in the partial sun
Threshing and winnowing
The cumin seeds are beaten out by threshing the dried plants with sticks. The seeds are then further dried to 10% moisture content, either by placing on mats or trays in the sun or by using a drier if the conditions are too humid. The dried seeds are winnowed using a traditional winnowing basket to remove the dirt, dust, leaves and twigs.
Grinding
Grinding can be a method of adding value to a product. However, it is not advisable to grind spices. After grinding, spices are more vulnerable to spoilage. The flavour and aroma compounds are not stable and will quickly disappear from ground products. The storage life of ground spices is much less than for the whole spices. It is very difficult for the consumer to judge the quality of a ground spice. It is also very easy for unscrupulous processors to contaminate the ground spice by adding other material. Therefore most consumers, from wholesalers to individual customers, prefer to buy whole spices.
Packaging
Cumin seeds can be packaged in polythene bags of various sizes according to the market demand. The bags should be sealed to prevent moisture entering. Sealing machines can be used to seal the bags. Attractive labels should be applied to the products. The label needs to contain all relevant product and legal information – the name of the product, brand name (if appropriate), details of the manufacturer (name and address), date of manufacture, expiry date, weight of the contents, added ingredients (if relevant) plus any other information that the country of origin and of import may require (a barcode, producer code and packer code are all extra information that is required in some countries to help trace the product back to its origin). See the Practical Action Technical Brief on labelling for further information on labelling requirements.
Storage
Dried cumin seeds must be stored in moisture-proof containers away from direct sunlight. The stored seeds should be inspected regularly for signs of spoilage or moisture. If they have absorbed moisture, they should be re-dried to a moisture content of 10%. The storage room should be clean, dry, cool and free from pests. Mosquito netting should be fitted on the windows to prevent pests and insects from entering the room. Strong smelling foods, detergents and paints should not be stored in the same room as they will spoil the delicate aroma and flavour of the cumin.
Standards
The Indian standard for dried cumin is as follows: Cumin seeds are available as whole seeds and ground powder.