Coffee is one of the most widely-consumed food products globally. Unfortunately, it is susceptible to fungus or mold that produces toxins known as mycotoxins. Eating a food containing high levels of mycotoxins or regularly consuming a food with mycotoxins can make you sick or cause chronic health problems. As such, assuring the food safety of coffee beans is critical to public health, and ISO/IEC 17025:2017 provides the foundation for accurate and reliable food testing laboratories.
Is There Mold in Coffee?
While coffee beans themselves can be susceptible to mold, especially if not properly processed or stored, the main concern is mycotoxins: toxic chemicals produced by certain molds. Mycotoxins can be present in coffee, even when mold is not visible. The most concerning mycotoxins found in coffee are ochratoxin A (OTA) produced by Aspergillus ochraceus and Penicillium verrucosum and aflatoxins produced by Aspergillus flavus and Aspergillus parasiticus. OTA has been less studied, but it is believed to be a weak carcinogen; aflatoxin B1 is a known carcinogen and is considered to be one of the most toxic variants of aflatoxins.
These fungi thrive in warm, humid environments, making coffee-growing regions, particularly in tropical and subtropical climates, susceptible to contamination as well as roastery warehouses that have high moisture levels. Several studies have found measurable levels of mycotoxins in coffee beans—both roasted and unroasted—as well as brewed coffee:
- Of samples of green coffee beans from Brazil, 33% had low levels of OTA.
- Of coffee brews from commercially available coffee beans in Portugal, 18% contained OTA.
- Aflatoxins have been found in green coffee beans, the highest level in decaffeinated beans. Roasting reduced the levels by 42–55%.
Does Processing Coffee Beans Reduce Mycotoxin Levels?
Cleaning coffee beans, especially through methods like wet processing (or washed processing), can significantly reduce mycotoxin levels. Wet processing is a method that involves removing the coffee fruit from the beans before drying, and it considered the most effective way to eliminate most molds and mycotoxin. A study, for example, found that the highest contamination level of mycotoxigenic fungi was found among coffee samples collected from the soil surface, while the lowest contamination was found wet-processed coffee.
Processing coffee bean via roasting (i.e., the process of heating green coffee beans to develop their characteristic flavor and aroma) can significantly reduce mycotoxin levels. A study found that, during the industrial process of converting coffee beans into roasted coffee and soluble coffee, a reduction of up to 90% may occur in OTA levels. Another study found that roasting coffee beans also kills the molds that produce the mycotoxins and roasting can reduce OTA levels by 69–96%.
While wet processing and roasting reduce mycotoxin levels, it is not a guaranteed solution for complete elimination and their effectiveness can vary. As a result, ISO/IEC 17025:2017 is important for conducting reliable testing of coffee for mold.
Why Is Adhering to ISO/IEC 17025 Important for the Coffee Industry?
ISO/IEC 17025:2017 sets the international benchmark for the competence of testing and calibration laboratories, assuring that they operate with scientific precision and validated methods. This standard supports the food industry by making sure that laboratory data used in inspection and regulatory decisions is scientifically validated and independently verified. As such, ISO/IEC 17025:2017 can be relevant to coffee mold and mycotoxin testing because it provides a framework to assure the competence and reliability of testing laboratories . This standard ultimately protects public health and promotes fair trade practice by:
- Improving Accuracy and Reliability of Test results
- Enhancing Credibility and Consumer Confidence
- Aligning with national and international legal requirements to achieve Regulatory compliance
- Supporting for Food Safety Certifications
- Improving the Operational Efficiency and Cost Savings
ISO Standards for Good Hygiene For the Coffee Supply Chain
Ultimately, good manufacturing practices and hygiene throughout the coffee production and processing chain is highly recommended in order to reduce the risk of contamination of processed coffee. This includes high quality care and quality crop management, harvest, post-harvest storage and type of roasting.
ISO 22000, the international standard for a food safety management system, provides a framework for organizations to control food safety hazards throughout the food chain, which includes coffee production. It covers areas like hazard analysis, prerequisite programs, and communication. There are various other ISO standards that provide safety guidelines for coffee:
- ISO 9116 gives guidance on methods to be used to describe green coffee for sale and purchase, and is based on the terms of contract used in the international coffee trade.
- ISO 10470 provides a chart which lists the main five different categories of defects which are considered to be potentially present in green coffee as marketed throughout the world, whatever its species, variety, and after-harvest processing (wet or dry).
- ISO 8455 provides specific guidelines for the storage (temperature, humidity, ventilation, and light) and transport conditions of green coffee, aiming to minimize risks of infestation, contamination, and quality deterioration.