Penicillic acid in fruits: method development, validation by liquid chromatography–tandem mass spectrometry and survey in southern China

BACKGROUND Penicillic acid (PA) is produced by Aspergillus spp. and Penicillium spp., which are common postharvest and storage fungi of fruits. PA can be of concern for human health because of its toxicity and high fruit consumption by the population. However, no data on PA occurrence in various fruits have yet been reported. A quick, easy, cheap, effective, rugged and safe (QuEChERS) approach for PA determination in various fruits was developed and applied to explore PA incidence in fruits. RESULTS The modified QuEChERS procedure with extraction by ethyl acetate and purification by multi-walled carbon nanotubes (MWCNTs), primary secondary amine (PSA) and octadecyl silane (C18) was established to determine PA in various fruits by high-performance liquid chromatography–tandem mass spectrometry (HPLC-MS/MS). The average recoveries were 72.9–102.2% and relative standard deviations (RSDs) were 1.3–7.9%. A total of 161 fruits samples, including kiwi, apple, peach, grape and mandarin/orange, were collected in southern China. The incidence of PA in fruits was 14.9% and the levels of PA contamination were 0.200–0.596 μg kg −1 . Our results suggested that orange/mandarin, grape and kiwi were favorable matrices for Aspergillus spp. and Penicillium spp. to produce PA, rather than peach and apple. CONCLUSION To the best of our knowledge, this is the first report about PA contamination in various fruits in China. Our study emphasizes the necessity of the current established method, which could be used for continuous monitoring of PA and reducing the health risk to Chinese consumers. © 2020 Society of Chemical Industry