1Brian Tyler, 1Jennifer A. Burgess, 2Pat Sacchetta
1Waters Corporation, Milford, MA, USA, 2Waters Australia Pty Ltd

Patulin is a mycotoxin produced by several Penicillium, Aspergillus, and Byssochlamys mold species that are commonly found on apples. Apples, which have been damaged or bruised prior to processing, are more susceptible to contamination by patulin-producing molds.
Proper handling and storage of apples is important to prevent the growth of patulin producing molds. When patulin-contaminated apples are processed into juice high levels of patulin are possible. The thermal stability of patulin prevents its decomposition during pasteurization.
The effects of patulin on humans are not known but intestinal lesions and stomach hemorrhages have been observed in mice and rats. Owing to this toxicity, the
U.S. FDA has set a maximum residue level (MRL) of 50 μg/kg of patulin in apple juice and apple juice concentrates.1 Other countries including China, Japan, and the EU have also set the maximum contamination of patulin to 50 μg/kg in apple juice products. The EU also has lower limits for patulin in solid apple products
(25 μg/kg), such as apple puree, and products designed for infants and young children (10 μg/kg).2
In order to protect both producers and consumers, accurate testing is required to prevent the contamination of apple juice with patulin. Patulin testing has typically employed LC separation with UV detection at 273 nm. Also absorbing at this wavelength, however, is 5-hydroxymethylfurfural (HMF), which is produced in the pasteurization of apple juice.