What are the mycotoxins in kodo millet? A Guide to Contamination and Safety

November 11, 2025 •

3 min read

Historically documented cases of "kodo poisoning" in both humans and animals, dating back to 1922, highlight the long-standing risk associated with contaminated grains. This poisoning is caused by mycotoxins in kodo millet, specifically potent fungal secondary metabolites like cyclopiazonic acid (CPA). When environmental conditions, such as rainfall during harvest, favor fungal growth, this otherwise nutritious grain can become toxic and unsafe for consumption.

Quick Summary

Kodo millet can be contaminated by mycotoxins like cyclopiazonic acid (CPA), a neurotoxin and hepatotoxin produced by Aspergillus and Penicillium fungi. Contamination is a risk when the grain is exposed to moisture during harvest or storage, and it can cause severe poisoning if consumed.

Key Points

Primary Threat: The main mycotoxin in contaminated kodo millet is cyclopiazonic acid (CPA), a potent neurotoxin and hepatotoxin.
Fungal Culprits: CPA is produced by fungal species such as Aspergillus flavus and Aspergillus tamarii, which infest the grains.
Risk Factors: High moisture, particularly rainfall during harvest, and improper storage conditions are the primary catalysts for fungal contamination.
Detection Methods: Visual inspection is unreliable; detection requires advanced techniques like HPLC, LC/MS, or rapid tests such as ELISA.
Serious Health Effects: Contaminated kodo millet can cause severe poisoning in humans and animals, affecting the nervous, cardiovascular, and gastrointestinal systems.
Effective Management: Preventing poisoning relies on a combination of good agricultural practices, proper post-harvest drying and storage, and biocontrol strategies.
Multi-Toxin Risk: Co-contamination with other mycotoxins, such as aflatoxins and fusarium toxins, is also possible and can increase health risks.

The Primary Mycotoxin in Kodo Millet: Cyclopiazonic Acid (CPA)

Extensive research identifies cyclopiazonic acid (CPA) as the main mycotoxin in "kodo poisoning". This neurotoxin and hepatotoxin damages the nervous system and liver. It is produced by specific molds infesting millet under certain environmental conditions, not an inherent part of the grain.

Fungal Producers of CPA

Several fungal species producing CPA can contaminate kodo millet:

Aspergillus flavus: A common soil fungus, a major CPA producer in kodo millet.
Aspergillus tamarii: Directly linked to kodo millet contamination and kodua poisoning outbreaks.
Penicillium species: Certain species, including Penicillium cyclopium, produce CPA.

Conditions Favoring Fungal Contamination

Kodo millet is vulnerable to mycotoxin contamination when conditions suit fungal growth:

Moisture and humidity: High levels, especially from rain during harvest, promote mold growth.
Inadequate storage: Poor post-harvest handling and humid storage lead to storage mold proliferation.
Warm temperatures: Fungi thrive in the warm, humid climates where kodo millet is grown.

Health Impacts of CPA Exposure

Ingesting CPA-contaminated kodo millet causes severe health issues in humans and animals:

Neurological effects: Symptoms include giddiness, tremors, and loss of mobility.
Cardiovascular issues: Can cause rapid pulse and cardiomyocyte damage.
Hepatotoxicity: CPA is a hepatotoxin, causing liver damage.
Gastrointestinal distress: Often includes vomiting and digestive upset.

Comparison of Mycotoxin Contamination Control

Preventing mycotoxin contamination requires a multi-faceted approach.


Strategy	Description	Effectiveness	Limitations
Good Agricultural Practices (GAPs)	Proper harvest timing and protection from rain.	Highly effective preventative measure.	Requires consistent application and is weather-dependent.
Proper Post-Harvest Storage	Drying and storage in airtight containers.	Crucial for preventing storage mold growth.	Can be difficult for smallholder farmers with limited resources.
Biocontrol Agents	Using non-toxigenic fungal strains to outcompete toxic ones.	Shows promise in reducing mycotoxin levels.	Requires long-term application and specialized knowledge.
Chemical Detoxification	Treating grain to inactivate mycotoxins.	Useful for remediation, but often ineffective due to toxin stability.	Does not solve the root cause and can affect food quality.

Potential Co-Contamination with Other Mycotoxins

While CPA is the main concern, co-contamination with other mycotoxins is possible in millets. Fungi producing CPA, like some Aspergillus species, can also produce aflatoxins. Millets are also susceptible to Fusarium species, which produce fumonisins, zearalenone, and deoxynivalenol. Co-contamination can lead to increased health risks through additive or synergistic effects.

Testing for Mycotoxin Contamination

Detecting mycotoxin contamination is impossible visually. Advanced chemical analysis is needed:

Chromatographic methods: HPLC and LC/MS provide precise identification and quantification.
Immunoassays: Rapid tests like ELISA and LFAs are used for on-site detection.

Conclusion

Kodo millet, a nutritious grain, faces a health risk from mycotoxin contamination, mainly cyclopiazonic acid (CPA). Fungal species like Aspergillus and Penicillium cause this under moist conditions during harvest and storage. Effective mitigation includes good agricultural practices, proper storage, and advanced detection. Research into biocontrol and host resistance is vital for safety. Raising awareness and implementing robust management ensure the safe consumption of kodo millet, protecting health from mycotoxin poisoning.

For further reading on mycotoxin management and food safety, the following resource provides a comprehensive overview: Millets: Journey from an Ancient Crop to Sustainable and Healthy Food.

Frequently Asked Questions

No, kodo millet is not inherently poisonous. It is a nutritious grain that becomes toxic only if it is contaminated by specific molds that produce mycotoxins, particularly under moist and humid conditions during harvest or storage.

'Kodo poisoning', also known as 'kodua poisoning', is the illness caused by consuming kodo millet contaminated with mycotoxins. It primarily affects the nervous, cardiovascular, and gastrointestinal systems.

Symptoms of kodo millet poisoning can include vomiting, giddiness, unconsciousness, tremors, rapid pulse, and in severe cases, liver damage or heart problems.

It is virtually impossible to detect mycotoxin contamination in kodo millet with the naked eye, as infected grains may appear fresh. Specialized chemical tests, like HPLC or ELISA, are required for accurate detection.

No, mycotoxins like cyclopiazonic acid are highly stable and resilient. Standard food processing methods, including cooking at high temperatures, do not effectively eliminate them.

Farmers can prevent contamination by using good agricultural practices, such as harvesting at the right time, protecting grains from rain, and ensuring proper drying and storage in airtight containers.

Yes, millets can also be contaminated by other mycotoxins, such as aflatoxins and fusarium toxins (like fumonisins and zearalenone), especially in regions with specific climatic conditions.

Proper storage, which includes drying the grains sufficiently and using airtight containers, prevents the growth of storage fungi like Aspergillus and Penicillium that produce mycotoxins.