What is Patulin?
Patulin is a toxic substance produced by molds that may grow on apples. In the past, patulin has been found to occur at high levels in some apple juice products offered for sale. Patulin is a mycotoxin produced by certain species of Penicillium and Aspergillus, often detectable in mouldy fruits and their derivatives. On the basis of a PMTDI of 0.4 micro gram/kg bw, limit values of 50 micro-grams/kg or 50 micro-grams/l of patulin have been set in fruit derivatives. In rotten apples, not only was the amount of patulin extraordinarily high in the rotten area, but the mycotoxin had also spread to the part unaffected by mould. The data presented in this study indicate that the intake of patulin with apple derivatives is usually below the tolerable level of 0.4 microgram/kg bw/day, but since the patulin content in apples can vary considerably, the quality of fruits used in the production of apple derivatives should be strictly controlled in order not to exceed the safe limits.
Adverse Effects of Patulin
Patulin exhibits a number of toxic effects in animals and its presence in food is undesirable. Neurotoxic Patulin can be responsible for acute effects including nausea, vomiting, and other gastrointestinal issues. It can affect a developing fetus, the immune system, the nervous system, the gastrointestinal tract, and can potentially cause DNA damage.
Sources of Patulin
Patulin is produced by several different fungi, but primarily from Penicillium species. Patulin has been detected in apples, pears, bananas, peaches, pineapple, blueberries, apricot, cherries, and grapes infected with Penicillium species. It has been associated recently with vegetables, cereal grains, and silage as it spoils. Patulin is associated with fruit, especially apples, exhibiting brown rot or other spoilage characteristics. Invading the fruit through insect damage, bruises, cracks, or other open spots, it can also affect varieties of fruit that exhibit an open calyx. Trimming just the rotten tissue was not enough to exclude all patulin. At 1 cm from the periphery of the rotten area, no patulin could be detected
Patulin is very stable in fruit juices because the presence of sucrose within the juice actually protects patulin from degradation during heat treatments. A high risk of toxin formation is associated with fresh pressed juices or ciders made from spoiled or low quality fruits. Conversely, patulin contamination is often not associated with vinegars or alcoholic beverages due to interaction of the mycotoxin and yeasts during the fermentation process.
Testing of Patulin
The FDA has set an upper limit of 50 μg/kg for patulin in apple juice and apple juice concentrates. Testing for the presence of patulin in food products is not simple, most patulin testing occurs via the use of HPLC (high performance liquid chromatography)-UV and/or liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS) analyses within a laboratory.
Methods to Contol Patulin Production
- Minimise insect and bird damage to apples can help to prevent mould infection and patulin production before harvest.
- At harvest, rotten and damaged apples should be discarded, as these are much more likely to contain patulin.
- Storage at temperatures of less than 10oC is also a useful control measure.
- Physical separation of mouldy and damaged apples before processing will help to reduce patulin levels in apple juice and other apple products.