Cooperative Extension Publications

By Gulsun Akdemir Evrendilek, Ph.D., Associate Extension Professor and Seafood Technology and Food Safety Specialist, The University of Maine Cooperative Extension.

Reviewed by Robson Machado, Ph.D., Associate Extension Professor and Food Scientist, The University of Maine Cooperative Extension.

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Why Are Spices Important for Food Safety?

Spices are more than just a way to add flavor to food. They also help keep food from spoiling. For thousands of years, people have used spices to preserve food and stop it from going bad too quickly. Many spices contain natural compounds such as phenols, terpenes, and alkaloids that can slow or even stop the growth of harmful bacteria and mold, which can cause foodborne illnesses. By using these spices, we can help food last longer and stay fresh.

Spices are a big part of the food industry. They are found in everything from chips and sauces to canned foods and frozen meals. Some, like garlic and turmeric, are even known for their health benefits. But while spices are helpful, they can also carry risks. Because many spices come from plants native to warm, humid climates, they can easily absorb moisture if not stored correctly. This can lead to the growth of mold and other safety issues.

Additionally, spices can sometimes be a source of contamination from bacteria, such as Salmonella, or from molds that produce harmful toxins. To get the most out of your spices, you need to know three things:

• their importance,
• how they make food safer,
• and the right way to store and handle them.

Whether you’re cooking at home, in a restaurant, or working in food processing and formulation, understanding the role of spices in food safety can help you make smarter choices in the kitchen and food production.

Key Benefits of Spices for Food Safety

Antimicrobial Properties

Some spices have natural antimicrobial properties, meaning they can help fight bacteria, fungi, and viruses that cause foodborne illnesses. Here are a few examples:

• Cinnamon: known to be effective against Escherchia coli and Salmonella, two common foodborne pathogens.
• Garlic: contains allicin, a powerful natural antimicrobial agent.
• Turmeric: curcumin, the active compound in turmeric, has been shown to help preserve food by reducing bacterial growth.
• Cloves and Oregano: contain essential oils with strong antimicrobial effects.

Antioxidant Effects

Many spices, including rosemary, oregano, and cloves, are rich in antioxidants. These compounds help prevent oxidation, which can cause food to spoil, lose its flavor, and become unsafe to eat over time. By slowing down the oxidation process, spices help maintain food quality and freshness.

Enhancing Thermal Processing

• Garlic and black pepper: their antimicrobial properties are more potent when activated by heat.
• Ginger and cinnamon: can enhance the effectiveness of thermal treatments in reducing bacteria in food.

Adding Spices at the Last Moment During Cooking

Many people prefer adding spices toward the end of cooking to preserve their flavor, but this practice can also impact food safety.

Risks of Adding Spices Late

Microbial Contamination

Raw or unprocessed spices may carry bacteria such as Salmonella or E. coli. If these spices are added at the end of cooking, they may not be exposed to enough heat to kill harmful microbes.

Reduced Antimicrobial Efficacy

Some spices, such as garlic and black pepper, become more potent when heated. Adding them too late may reduce their ability to fight bacteria.

Moisture Exposure and Contamination Risk

When spices are added during cooking, exposure to steam or vapor can introduce moisture into spice containers. This increased moisture content can create favorable conditions for microbial growth, including molds that produce mycotoxins. To avoid this risk, always use a dry spoon to take out spices and avoid shaking spice containers directly over steaming pots.

Best Practices for Safe Spice Use

• Choose heat-treated or irradiated spices to reduce the risk of contamination. For irradiated spices, look for the “Radura” symbol (Fig. 1) and the words “Treated with Radiation” on the packaging, which is mandatory. Unfortunately, heat-treated spices may not mention this on their labels, as it is not mandatory; however, some brands do include it anyway.
• Incorporate spices during cooking so they have enough time to release their antimicrobial compounds.
• Store spices properly in cool, dry, and airtight containers to prevent contamination and spoilage.
• Avoid exposing spice containers to steam by transferring spices to a dry surface before adding them to food.

Mycotoxins in Spices: A Hidden Risk

Spices can sometimes be contaminated with mycotoxins—harmful substances produced by molds such as Aspergillus and Penicillium. Mycotoxins, including aflatoxins and ochratoxins, are toxic and can cause serious health problems, such as liver damage, immunosuppression, and even cancer.

Why Do Mycotoxins Occur in Spices?

• Many spices, such as chili, paprika, pepper, nutmeg, and turmeric, are grown in warm and humid climates, which create ideal conditions for mold growth.
• Poor harvesting, drying, and storage practices can increase mold contamination and mycotoxin production.
• Improper storage, including exposure to moisture from cooking steam, can raise humidity levels in spice containers and encourage mold growth.

How to Minimize Mycotoxin Risks

Sourcing and Processing

To minimize risk, buy spices from retailers you trust, such as well-known grocery stores or specialty spice shops. These businesses are more likely to source their products from reputable suppliers with established food safety practices.

Proper Storage Conditions

1. Store spices in a dry environment with humidity levels below 70%.
2. Use airtight containers to protect spices from moisture and prevent mold growth.
3. Avoid placing spice containers near sources of steam or vapor, such as boiling pots or dishwashers.

Heat Treatment and Irradiation

Heat treatment and irradiation can reduce mold contamination in spices. However, they do not eliminate mycotoxins that have already formed, so proper sourcing and storage remain critical.

Key Takeaways

• Spices help keep food safe by reducing microbial growth and oxidation.
• Adding raw spices too late in cooking can introduce harmful microbes if they are not properly processed.
• Moisture exposure from cooking steam can increase microbial load in spice containers and promote mycotoxin formation.
• Mycotoxins in spices pose a serious health risk, but proper sourcing, storage, and testing can help prevent contamination.

By following these best practices, you can enjoy the flavor and health benefits of spices while ensuring food safety for yourself and your family.

Additional Resources

University of Maine Cooperative Extension Tips for Using Herbs and Spices

References

Awulachew, M.T., 2024. The Possible Use of Herbs and Spices in the Food Processing and Food Safety In Herbs and Spices. New Perspectives in Human Health and Food Industry. IntechOpen. DOI: 10.5772/intechopen.1004028

Gottardi, D., Bukvicki, D., Prasad, S. and Tyagi, A.K., 2016. Beneficial effects of spices in food preservation and safety. Frontiers in microbiology, 7, p.1394. https://doi.org/10.1016/j.ijfoodmicro.2021.109295

 Gurtler, J.B. and Keller, S.E., 2019. Microbiological safety of dried spices. Annual Review of Food Science and Technology, 10(1), pp.409-427. https://doi.org/10.1146/annurev-food-030216-030000

Israni, R.K. and Khurana, S.C., 2022. Food safety issues in spices and herbs–Indian perspective: A review. International Journal of Innovative Horticulture, 11(2), pp.274-287.

Karam, L., Salloum, T., El Hage, R., Hassan, H. and Hassan, H.F., 2021. How can packaging, source and food safety management system affect the microbiological quality of spices and dried herbs? The case of a developing country. International Journal of Food Microbiology, 353, p.109295. https://doi.org/10.1016/j.ijfoodmicro.2021.109295

Lee, S.H., Mun, K.H., Kim, N.Y.S. and Kim, J.B., 2018. Evaluation of microbiological safety of commercial spices. Food Science and Preservation, 25(6), pp.706-714. DOI: https://doi.org/10.11002/kjfp.2018.25.6.706

Thanushree, M.P., Sailendri, D., Yoha, K.S., Moses, J.A. and Anandharamakrishnan, C., 2019. Mycotoxin contamination in food: An exposition on spices. Trends in Food Science & Technology, 93, pp.69-80.https://doi.org/10.1016/j.tifs.2019.08.010

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Information in this publication is provided purely for educational purposes. No responsibility is assumed for any problems associated with the use of products or services mentioned. No endorsement of products or companies is intended, nor is criticism of unnamed products or companies implied.

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