Patulin - A Mycotoxin Related to Molds

What is it?

Patulin is a toxic chemical produced from a number of molds such as Penicillium and Aspergillus. Although apples tend to be the major source, any moldy or rotten fruit could contain this toxin.

Why is patulin a concern?

Patulin has been found to cause a range of health problems in laboratory animals. There is concern that similar effects may occur in humans, which is why exposure should be kept as low as practically possible.

What is the level of risk?

The United States Food and Drug Administration (FDA) believes risks are minimal for consuming juice containing patulin if processors control the level to 50 mg/kg (50 ppb) or lower. The international organization, Codex Alimentarius Commission (Codex) is considering the possible reduction of the maximum level of 50 ppb to 25 ppb due to the high intake of apple juice by young children and the possibility that they may exceed the acceptable daily intake.

How can you control patulin levels in your juice?

The potential for high patulin levels to appear in fruit juice will depend on several factors. There is no one factor that will determine, in all situations, whether the juice contains high levels of patulin. The most significant indicators are:

• Were fallen apples (grounders) used in the production of the juice? Fallen apples are more likely to contain high levels of patulin than apples picked from the tree.
• What is the condition of the apples at the time of harvest? Apples with visible damage (eg. rots, wounds, bird or insect damage etc) are more likely to contain high levels of patulin than apples without such visible defects.
• How are the apples handled prior to storage? Apples that have been bruised during handling are more likely to develop patulin.
• What are the storage conditions of apples? Mold growth normally occurs in a warm environment. Apples stored under abusive temperature or atmospheric conditions are more likely to have higher levels of patulin than those apples stored under controlled conditions.
• Are apples monitored during storage? Stored apples should be examined regularly for rot or mold and remove the fruit before extensive damage occurs.
• Are apples culled or trimmed prior to juice production? Including a process step prior to pressing to physically remove any apples that show visible mycelia or rot will reduce patulin levels.

Not all apple varieties are equally affected by these factors. Evidence suggests that varieties with an open calyx are a greater risk for patulin development within the core of the apple. In such a situation, damage to the fruit is not easily detected and the apple may not be removed prior to pressing. This is one reason why it is more practical for reduction rather than prevention of this toxin.

Other options to reduce toxin levels at processing?

Beyond the quality of the apple at time of processing, adding sulfur dioxide (SO2) as a food preservative at levels between 25 and 50 ppm will destroy patulin in the apple juice. Patulin is also destroyed by fermentation which means it is not found in either alcoholic fruit beverages or vinegar produced by fruit juices. Patulin will however, survive the pasteurization process if present in the juice.