Patulin in apples and apple products, and how to reduce it
What it found
A mold called Penicillium expansum infects damaged apples and produces patulin, a toxin that has been found in apple juice and other apple products around the world.
The authors describe ways to lower patulin from the orchard through storage and processing.
What they found
Animal and lab studies
Apple traits and patulin
Apples with firm flesh, lower ethylene production, and more polyphenols are less likely to accumulate patulin. Over-ripe or soft apples are more susceptible to blue mold and patulin.
Storage temperature
The effect of storage temperature on patulin is complicated. In some apple varieties, the highest patulin was found when stored above 20 °C, but in others higher levels were seen at 1 °C or 4 °C compared to 22 °C or 23 °C.
Studies in people and animals
Reducing patulin
Culling rotten apples, washing with hot water, and some non-thermal treatments like UV light and high pressure can lower patulin. Biological control agents like antagonistic yeasts and bacteria also show promise.
Other findings
Mold and patulin
Penicillium expansum is the most common cause of blue mold decay in apples and the main producer of patulin. It grows well even at 0 °C or below, so infection can still happen during cold storage.
Patulin in apple products
Surveys have found patulin in apple juice and cider in many countries. In one analysis of 35 apple products from Northeast China, 20% exceeded the regulatory limit of 50 µg/kg, with the highest level at 94.7 µg/kg in apple juice concentrate.
Heat treatment
Pasteurization only partly reduces patulin. When apple juice was pasteurized for 30 seconds at 90 °C, patulin dropped from 433 µg/L to 262 µg/L, a 39.6% reduction.
What the authors conclude
- They say that efforts are still needed to make children and adults feel safe while enjoying the health benefits of processed apple-based products, without concerns about patulin contamination.
- They advise that the most promising method for patulin reduction is the use of biological control agents, but the toxicity of breakdown products and the mechanisms behind detoxification need more research.
- They recommend simple practices like culling rotten apples and washing with hot water before juice pressing.
How it was done
Patulin contamination in apple products has been a worldwide problem without a satisfactory solution. The authors wanted to bring together what affects patulin buildup in apples and what can be done to reduce it.
They gathered and discussed published research from the last decade on the mold, apple traits, storage and processing conditions, detection methods, and control strategies. No new experiments were run.
What it can’t tell you
- This is a review of other studies, so it cannot provide new experimental evidence on patulin or its health effects.
- The studies described used different apple varieties, mold strains, and conditions, so the results may not apply to all situations.
- The long-term health effects of patulin in people are not known from this paper.
Who paid
- Conflicts
- The authors declare no conflicts of interest.
- Authors work at
- Nanjing Agricultural University, China; Guelph Research and Development Centre, Canada
The paper
- Title
- Patulin in Apples and Apple-Based Food Products: The Burdens and the Mitigation Strategies
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Zhong L, Carere J, Lu Z, Lu F, Zhou T (2018). Patulin in Apples and Apple-Based Food Products: The Burdens and the Mitigation Strategies. Toxins. doi:10.3390/toxins10110475Free full textPubMed 30445713DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error