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To prevent the generation of drug-resistant fungi from long-term exposure to microorganisms, cinnamic acid (CA), a natural effective antifungal agent, was successfully coupled with poly-dopamine magnetic nanoparticles (CA-DMPs). Due to the low solubility of CA, the saturated solution of CA (1.61 mg/mL, 45 • C) had no antifungal effect. Contrarily, CA-DMPs showed a good antifungal effect. The resulting heatstable and reusable antifungal CA-DMP composite particles were superparamagnetic (49.79 emu g −1 ) and had an average diameter of 25.01 ± 1.36 nm. The novel composites showed good antifungal activity and excellent recycling performance, the sterilization rate of CA-DMPs remained above 96% after seven consecutive running cycles.CA-DMP composites could damage the fungal cell wall and membrane system, leading to the leakage of cell inclusions. Furthermore, transcriptome analysis of Aspergillus fumigatus treated with composites showed that 466 differentially expressed genes were primarily associated with cell wall membrane, membrane transporters, energy metabolism, genetic expression, and oxidation-reduction. The effect of CA-DMPs in inducing mitochondrial membrane dysfunction might result in the disruption of energy metabolism and REDOX homeostasis. Overall, the results reported herein provide new insight into the potential antifungal nanomaterials. In vitro antifungal experiments performed on cherry tomatoes confirm the application potential of the synthesized material in the field of fruit and vegetable preservation.

BACKGROUND This study investigates the efficacy of short peptides secreted by Bacillus subtilis for fungal inhibition in fresh‐cut pumpkin and for maintaining its shelf life. RESULTS Low‐molecular‐weight filtrate (LC < 1000 Da) of B. subtilis culture (BC) significantly lowered the total number of molds on fresh‐cut pumpkin compared with the untreated control and a BC group after storage. Low‐molecular‐weight filtrate prevented the deterioration of sensory quality in a pumpkin incision, and reduced pectinase activity. It also inhibited the growth of Phytophthora capsici and Penicillium chrysogenum, and the activity of β‐1,3‐glucan synthase (GS) secreted by both molds. Fifty‐seven GS‐inhibiting peptides were screened from 95 LC peptides with two to five amino acid residues. The two most potent peptides, AWYW and HWWY, had strongly suppressive effects on the growth of P. capsici and P. chrysogenum. CONCLUSION Our study demonstrated that short peptides present in B. subtilis culture can play an important role in the maintenance of fresh‐cut pumpkin by suppressing fungal growth. © 2019 Society of Chemical Industry