Patulin in Fresh Fruits

As the popularity of LC/MS/MS methods for detection of mycotoxins continues to rise, more laboratories are turning to this technology to accurately detect patulin contamination at low levels of parts per billion (ppb). Couple this LC/MS/MS technology with the use of a C-13 Isotope Labeled Internal Standard for patulin and the method has great sensitivity and accuracy in even complex matrices. The proper use of the C13 Internal Standard allows the LC-MS/MS system to be equilibrated to matrix enhancements and matrix suppressions for accurate quantitation. Many laboratory methods can detect patulin contamination with limits of detection at 2 ppb.

Regulatory limits for the presence of patulin in food have been established in the European Union (EU) and China. To date official regulatory limits are not in place within the U.S.; however, recommendations or guidelines have been established for patulin inclusions within foods. For the U.S., these guidelines have been set at 50 microgram per kilogram (ug/kg) of patulin in apple juice, apple juice concentrates based upon single strength inclusion, and apple juice products. The guideline of 50 ug/kg by the FDA allows for a negligible risk of adverse health effects from the consumption of patulin within apple juice products over a routine period of time. China has established regulatory limits of 50 ug/kg in apple and hawthorn products. The EU has established regulatory limits of 10 ug/kg in apple juice and solid apple products for infants and young children, 25 ug/kg in solid apple products, such as apple puree, intended for direct consumption, and 50 ug/ kg in fruit juices and in drinks containing apple juice or derived from apples.

Sampling Issues

Proper sampling techniques must be employed in order to test for and detect the accurate presence of patulin within any raw fruit product or finished fruit puree, sauce, or juice. Based upon a study conducted by T.B. Whitaker and J.W. Dickens (1974), 98 percent of analytical error comes from improper sampling of the product being tested. Eighty-eight percent is attributed to sampling errors and 10 percent is attributed to sub-sampling errors from that initial sampling lot. Mycotoxins have a distribution problem within food and feeds—they are not evenly distributed across the lot of food being tested such as in proteins. Mycotoxins can exhibit clustering across the lot that can lead to either elevated or false positives above threshold or false negatives.

For proper sampling to occur, proper equipment must be utilized that pulls samples randomly from numerous spots across the lot. For raw fruits, this would include multiple samples from different bins or different locations of the bin. For purees, sauces, or juices, this would include multiple samples from different time points of the production process in order to capture a beginning, middle, and end sample at a minimum. The sampling plan should be an established protocol that is utilized in an identical pattern every time collection of a sample is to occur. By performing sampling in a routine and throughout random process, the confidence in an analytical result can be greatly improved.

The ultimate goal in sampling and analytical testing is to determine the accurate result. Ideally no patulin contamination will be detected within the fruit crops; however, should an occurrence of patulin be detected, it is critical for the sampling plan and analytical methodology employed to be sound and robust such that an accurate result is obtained for all involved parties.

Swoboda is laboratory director, quality manager at Romer Labs, Inc. Reach her at [email protected].

References Furnished Upon Request