Apple Quality, Storage and Washing Effects on Patulin Levels in Apple Cider

In the last issue of the newsletter, a recent research report in the Journal of Food Protection was mentioned. The report presented information on how apple quality, storage and washing treatments affected patulin levels in apple cider.

One of the areas this study looked at was how apple harvesting methods and culling affects patulin levels in cider pressed from fresh (non-stored) apples.

Seven different apple cultivars were harvested and classified according to method of harvest - tree picked or ground harvested. The tree picked fruit were divided into two groups, culled and not culled. Visibly damaged apples were removed from the culled group (apples showing mold, bird pecks, skin breaks, hail damage or major bruising). In the unculled group, 10 to 70% of the apples were visibly damaged. It is worth noting that no patulin was detected in cider pressed from tree picked fruit (culled or unculled).

In contrast, cider produced from ground harvested fruit contained up to 374 micrograms of patulin per litre and for specific cultivars was significantly higher than the same cultivars of tree picked fruit. The United States Food and Drug Administration (FDA) believes risks are minimal for consuming juice containing patulin if processors control the level to 50 micrograms or lower. These results illustrate a wide variation of patulin levels between varieties, which may relate to the different fruit cultivar susceptibility to P. expansum rot and to contamination with patulin.

Cider samples were also analyzed for bacterium, yeast and mold levels. Microbial levels showed similar trends to patulin levels, with all cultivars of ground harvested apples having nearly a 2 log higher count than cider produced from tree picked fruit. The results of this study illustrate that the patulin level in the cider may be a good indicator of the quality of apples used. Patulin and microbial levels may be substantially reduced when tree picked fruit are used in cider production instead of ground harvested fruit. The findings of this research project and other supporting documentation suggest that dropped fruit should not be used in the manufacturing of all apple products.

For detailed report information and supporting documentation refer to the Journal of Food Protection, Vol. 66, No. 4, 2003, Pages 618-624

"Apple Quality, Storage, and Washing Treatments Affect Patulin Levels in Apple Cider" by Lauren S. Jackson, Tina Beachham-Bowden, Susanne E. Keller, Chaitali Adhikari, Kirk T. Taylor, Stewart J. Chirtel and Robert I. Merker