The effects of curcumin-mediated photodynamic technology (CUR-PDT) on the mycelial growth and patulin (PAT) secretion of Penicillium expansum were investigated. Mycelia of P. expansum grew vigorously after 5 days of solid culture, and PAT secretion increased 6.5 times. Short-term treatment with curcumin slightly inhibited the mycelial growth and PAT secretion. At a low dose of 0.275 W/cm2, 50~300 μmol/L curcumin significantly reduced the colony diameter (0.84 cm) and mycelial weight (68.37 mg) of P. expansum in solid culture, and the inhibition rate of PAT secretion was 83.85%. Following the inoculation of Red Fuji apples with PDT-treated mycelia and culture for 8 days, the inhibition rate of lesion diameter was positively correlated with the concentration of curcumin, with the maximum inhibition rate of 49.38%. The distribution of PAT in the fruit was closely correlated with the mycelial expansion ability, and the lesion proportion and PAT content were 0.09% and 18.02% respectively. Therefore, CUR-PDT can significantly inhibit the mycelial growth and PAT secretion of P. expansum.
