Other decontamination techniques for herbs and spices 75
4.2 Preventive measures against contamination..................................
A code of hygienic practices for herbs and spices (whether whole, broken or ground,
mixes and blends or processed products) must be followed precisely to ensure quality.
It covers the minimum hygiene requirements during production, harvest and post-
harvest activities. Post-harvest technologies include curing, bleaching, drying,
winnowing, grading, processing (extraction of essential oil and oleoresin, freezing,
freeze-drying, dehydration, etc.) packing, transportation, storage and microbial and
insect disinfestations. The necessary measures are described below.
4.2.1 Production
∑ Seed material should be from a reliable source and devoid of pests and diseases.
∑ Contaminated crop residues and materials from animal, domestic and human
sources should not be used in crop production.
∑ Irrigation water should not be polluted or contaminated.
∑ Control measures for pests and diseases involving chemicals or biological agents
should only be undertaken with expert advice and with thorough knowledge of
the potential dangers to health.4.2.2 Harvesting and on-farm processing
∑ Curing (drying) may be done in sunlight or mechanically. If carried out
mechanically, all surfaces and machinery used should be clean to prevent
contamination.∑ The area used for drying crops in the sun should be a raised platform or concrete
floor inaccessible to domestic animals, and where dust contamination (by wind)
is minimized.∑ Precautions should be taken to prevent contamination by rodents, birds, insects
and other animals during drying and handling in the open.
Ta ble 4.1 Contaminants found in herbs and spices and their harmful effects
Contaminant Harmful effects
Extraneous matter (other parts of the same Reduces physical quality.
plant or other plants, sand, stones, etc.)
Moulds and bacteria Moulds change flavour. Some produce toxins.
Bacteria cause ill health and disease.
Insects (in the field and during storage) Carry disease-causing organisms,
damage the product, affecting physical quality,
and leave excreta. Some insect parts are harmful.
Spiders, mites and psocids Harmful to health. Excreta of some spiders is
toxic.
Rodent, animal and bird excreta and detritus Carry disease-causing organisms and reduce
quality of product.
Pesticides and chemicals Extremely harmful to health, may cause cancer.
Heavy metals, e.g., arsenic, zinc, Toxic to humans, may cause cancer.
copper, lead, mercury, etc.