Influence of storage temperature and apple variety on patulin production by Penicillium expansum.

This study examined the potential for patulin production in six different varieties of apples (Red Delicious, Golden Supreme, Gala, Fuji, Empire, and McIntosh) inoculated with Penicillium expansum spores and stored at two different temperatures (11 and 20.5 degrees C). Samples for patulin analysis were randomly taken from apples stored at different times, ranging from 21 to 93 days. While patulin was produced at both storage temperatures, apples incubated at 20.5 degrees C yielded significantly higher patulin concentrations than did those incubated at 11 degrees C. All apple varieties showed mold spoilage at both temperatures, except Red Delicious and Empire. A total of 44% of the samples analyzed showed patulin concentrations above the U.S. Food and Drug Administration regulatory limit (50 ppb). The highest patulin productions occurred in Golden Supreme (54,221 ppb) and McIntosh (52,131 and 48,457 ppb) varieties. Our results showed that careful culling of apples is essential for high juice quality, since high patulin levels in some apples varieties could result in a level greater than 50 ppb of this mycotoxin in the finished juice or cider, even when only one contaminated apple occurs in 1,000 apples.