84 Handbook of herbs and spices
herbs and spices is aflatoxin, produced by the fungi, Aspergillus flavus and Aspergillus
parasitics. Ochratoxin, produced by Aspergillus ochraceus, is sometimes found. These
fungi infect herbs and spices when moisture levels remain high after harvesting, for
instance if drying is delayed.
Aflatoxin is more commonly found in chili, ginger and nutmeg, among others.
There are four types of aflatoxin – B1, B2, G1 and G2. B1 is the most dangerous
among the four. Aflatoxin is carcinogenic and is not destroyed by cooking. The upper
limits in herbs and spices prescribed by the European Union are 5 ppb for B1 and 10
ppb for B1+B2+G1+G2. The USA permits a higher level of 20 ppb for all the
fractions together. The European Union is considering introducing the maximum
permissible limit of ochratoxin.
Some work has been done on hydrogen peroxide and ammoniation treatments to
remove aflatoxin from peanut protein, milk, cotton seed and other materials, but has
not been found to be effective. These techniques have not been tried on herbs and
spices. The best way to produce aflatoxin-free herbs and spices is through timely
harvest, immediate drying and good storage practices (Palle 1987).
It is also impossible to remove completely any pesticide residues or heavy metals
in herbs and spices, or even to reduce them to permissible limits, with presently
available techniques. Pesticide residues found in these products are mainly of three
kinds, organo-chlorine compounds, organo-phosphorus compounds and carbamates.
Some pesticides are systemic and their residues will be in the products until they
are denatured. Heavy metals are stable and their poisonous effect may continue
indefinitely. The best way to avoid health hazards in herbs and spices is to ensure that
any chemical pesticides used in crop production are applied in accordance with
the manufacturer’s instructions and government regulations for their use. Herbs and
spices should be grown on soils where heavy metal levels are low, and any possible
contamination with heavy metals during pre-harvest and post-harvest operations should
be avoided.
4.8 Sources of further information and advice....................................
ASTA’s Cleanliness Specifications: The American Spice Trade Association, 2025 M
Street, NW Suite 800, Washington, D.C. 20036. Website: http://www.astaspice.org.
HACCP Guide to Spices and Seasonings: The American Spice Trade Association,
2025 M Street, NW Suite 800, Washington D.C. 20036
Hsieh, R.C. et al. (1989), Process for Sterilization of Spices and Leaf Herbs, US
Patent 4, 844, 933.
Hsieh, R.C. et al. (1990), Apparatus for Sterilization of Spices and Leaf Herbs, US
Patent 4, 967, 651.
Importing Foods into the United States, HHS Publication No. FDA 84-2141, Department
of Health and Human Sciences, Public Health Service, Food and Drug Administration,
Washington D.C.Morgon, M.R.A., Smith, C.J. and William, P.A. (1992), Food Safety and Quality
Assurance – Application of Immunoassay System. Elsevier Applied Science, London.
Pesek, C.A., Wilson, L.C. and Hammod, E.G. (1985), Spice Quality: Effect of Cryogenic
and Ambient Grinding on Volatile Oils, J. Food Sc. 50(3): 599-601.
Spice Quality Control, The American Spice Trade Association, 2025 M Street, NW
Suite 800, Washington, D.C. 20036.