Abstract
We investigated the effects of apple varieties and their fruit components on mycotoxin production by Penicillium expansum inoculation. Among five major apple varieties in Japan, Jonagold showed substantially higher patulin production by P. expansum (ATCC 36200) than Fuji 12 and 16 days after inoculation. Although patulin production in Tsugaru, Sansa, and Orin varieties tended to be lower than that in Jonagold and higher than that in Fuji, no significant difference in production was detected among these apple varieties. Moreover, inoculation of Jonagold, Orin, and Fuji with three strains of P. expansum (Pa447, Pa452, and Pa553) isolated from naturally infected fruits resulted in higher patulin production in Jonagold than in Fuji and Orin. Citrinin production levels were not significantly different in either the five varieties inoculated with ATCC 36200 or the three varieties inoculated with Pa447, Pa452, and Pa553. In addition, no significant difference in expansolides A/B production by Pa447, Pa452, and Pa553 was observed among Jonagold, Fuji, and Orin. The total polyphenol and malic acid contents were positively correlated with patulin production, while the total free amino acid content was negatively correlated. These results suggest that the apple cultivar and the components in the fruit affect patulin production by P. expansum.
