What is Patulin?

Patulin is a mycotoxin, a toxic compound produced by certain types of fungi. It is predominantly produced by species of Penicillium, Aspergillus, and Byssochlamys. Initially discovered during World War II as a potential antibiotic, it was later found to possess toxic properties that posed significant health risks to humans and animals.

Chemical Structure and Properties

Chemically, Patulin is a polyketide lactone with the molecular formula C7H6O4. It is a colorless, crystalline substance that is soluble in water and organic solvents like ethanol. Its structure allows it to bind to various biological molecules, leading to its toxic effects.

Identification Methods

Several analytical methods are available for detecting Patulin, with High-Performance Liquid Chromatography (HPLC) being the most commonly used. HPLC offers high sensitivity and specificity in identifying the presence of Patulin in food samples.

What Foods Can Be Contaminated?

Common Food Sources

Patulin is most frequently found in rotten apples and apple-derived products such as apple juice, cider, and apple sauce. However, it is not exclusive to apples and can be found in other fruits like pears, peaches, and grapes. The toxin can also be present in moldy vegetables, cereals, and even in some processed foods that use these contaminated ingredients.

High-Risk Foods

Products that involve minimal processing or lack any heat treatment during their preparation are generally at higher risk of Patulin contamination. For example, unpasteurized apple cider can retain more Patulin compared to its pasteurized counterpart.

Identification in Food Products

Food producers often employ stringent quality control measures, including regular testing of raw materials and end products, to detect the presence of Patulin. Advanced techniques like Liquid Chromatography-Mass Spectrometry (LC-MS) are used to ensure the safety of food products. Companies also implement preventive measures like sorting and discarding visibly decayed fruits before processing to minimize the risk of contamination.

Consumer Tips

For consumers, the primary defense against Patulin exposure is avoiding visibly rotten or damaged fruits and vegetables. When purchasing processed food items, it is advisable to choose products from reputable sources that adhere to safety regulations.

How Does It Affect Human Health?

Acute Effects

Exposure to Patulin can lead to acute toxicological effects such as gastrointestinal issues, nausea, and vomiting. The toxin is also known to induce lesions in the gastrointestinal tract.

Chronic Exposure

Prolonged exposure to Patulin can have more severe health consequences. Studies on animals have shown potential immunotoxic, genotoxic, and even neurotoxic effects. Although comprehensive human studies are lacking, these findings suggest that chronic exposure could have significant health implications.

Vulnerable Populations

Certain demographics, such as children, elderly people, and those with compromised immune systems, may be more susceptible to the adverse effects of Patulin. These groups should exercise particular caution in the selection and consumption of food products that could potentially contain this mycotoxin.

Metabolism and Elimination

Patulin is absorbed through the gastrointestinal tract and is metabolized by the liver. However, it is rapidly excreted through urine, reducing the risk of bioaccumulation in the body. It’s important to note that the human body’s ability to efficiently eliminate Patulin does not negate the potential risks associated with its consumption.

Research Gaps

While the toxic effects of Patulin are reasonably well-characterized in animal models, further research is required to fully understand its impact on human health. Specifically, studies that look into the long-term consequences of exposure and potential synergistic effects with other toxins are essential.

How Common is Illness?

Incidence Rates

While precise incidence rates of Patulin-induced illnesses are not readily available, it is generally considered to be less common compared to other foodborne pathogens like Salmonella or E. coli. This is partly because Patulin does not survive well in a human host, and is rapidly excreted from the body.

Monitoring and Reporting

Surveillance mechanisms for tracking Patulin-related illnesses are not as robust as those for bacterial pathogens. This lack of data could contribute to an underestimation of the actual number of cases. Various governmental agencies, like the Centers for Disease Control and Prevention (CDC), do monitor mycotoxin-related illnesses but often do not specify the data for Patulin.

Factors Influencing Prevalence

The occurrence of Patulin-related illnesses can be influenced by several factors, such as geographical location, food consumption patterns, and the effectiveness of food safety measures in place. Countries with robust food safety regulations tend to have lower incidences.

Outbreaks and Recalls

There have been a few notable cases of Patulin contamination leading to product recalls. While these incidents are less frequent than recalls for bacterial contamination, they serve as a reminder of the ongoing risks associated with this toxin.

Where Does It Come From?

Origin of Contamination

Patulin is produced by a variety of fungi, notably by genera such as Penicillium, Aspergillus, and Byssochlamys. These fungi thrive in conditions where there is decaying plant matter, making fruits like apples and pears prime candidates for contamination. Fungal spores can infect fruits both in the field and during post-harvest storage.

Contamination during Food Processing

Although the risk exists in raw fruits, contamination can also occur during the food production process. Inadequate storage conditions, such as high humidity and poor ventilation, can promote fungal growth, further elevating the risk of Patulin contamination. The European Food Safety Authority has highlighted the importance of good manufacturing practices to mitigate this risk.


While not as common, cross-contamination is another avenue through which Patulin can enter the food chain. For instance, using contaminated equipment or packaging materials can inadvertently introduce the toxin into otherwise clean produce.

How Is It Affected By Environmental Factors?


The production of Patulin is highly sensitive to temperature. Fungi that produce Patulin prefer a moderate temperature range, typically between 20°C to 30°C. Extreme temperatures, both high and low, can inhibit fungal growth and, consequently, Patulin production. The USDA has published guidelines that emphasize the importance of temperature control in storage facilities to minimize mycotoxin contamination, including Patulin.


High humidity levels can facilitate the growth of fungi responsible for Patulin production. Damp and poorly ventilated storage conditions are particularly conducive for such fungal growth. Many studies have shown a direct correlation between increased humidity and Patulin concentration in stored fruits.

Soil and Agricultural Practices

The type of soil and agricultural practices can also influence the risk of Patulin contamination. Acidic soils with poor drainage are generally more susceptible to hosting Patulin-producing fungi. Utilizing proper irrigation and soil management techniques can significantly reduce these risks.

How Can It Be Controlled?

Food Processing Methods

Several food processing techniques can effectively reduce or eliminate Patulin from contaminated food products. Heat treatment, such as pasteurization and boiling, has been found to significantly reduce Patulin levels. However, it’s essential to note that not all methods are entirely effective; for example, simple filtration processes are less effective in removing Patulin.

Quality Control and Sorting

One of the primary ways to control Patulin levels is through stringent quality control measures. Food producers often use optical sorting technologies to identify and remove contaminated fruits from the production line. Additionally, employing good manufacturing practices can substantially mitigate the risks.

Chemical Methods

Various chemical agents, such as sulfur dioxide and hydrogen peroxide, have been examined for their ability to degrade Patulin. These substances can sometimes be applied directly to foods or used to clean equipment that comes in contact with food.

Natural Remedies

Some research indicates that natural substances like essential oils from oregano and clove can inhibit the growth of Patulin-producing fungi. While these methods are not yet widely adopted, they offer a promising avenue for future control strategies.

Are There Rules and Regulations?

Global Standards

Various international organizations have set limits for acceptable levels of Patulin in food products. For instance, the World Health Organization (WHO) and the Food and Agriculture Organization (FAO) jointly recommend a maximum Patulin level of 50 µg/kg in apple juice. The European Union has similar guidelines, which also extend to solid apple products like apple puree and apple compotes.

United States Regulations

In the United States, the Food and Drug Administration (FDA) has issued guidelines for the apple juice industry, recommending a maximum Patulin concentration of 50 µg/L. These guidelines serve as a framework for state-level regulations and are actively enforced through regular monitoring and product recalls.

Enforcement and Monitoring

Regulatory agencies like the FDA in the United States and the European Food Safety Authority (EFSA) in Europe routinely conduct tests on food products to ensure compliance with Patulin standards. Non-compliant products are subject to recalls, and manufacturers may face legal repercussions.

Gaps and Future Directions

Although existing regulations provide a foundation for Patulin control, there is room for improvement, especially in the context of international trade. Harmonizing global standards and increasing public awareness are vital steps for better controlling this mycotoxin.

Resources and Further Readings

Patulin in Apples and Apple-Based Food Products

Patulin in food

Patulin and Human Health

Effect of Ambient pH on Growth, Pathogenicity, and Patulin Production

Patulin Contamination in Fruit Juices and Its Control Measures