Potential application of Fe2+ as antifungal agent in the food industry - Results in pitaya

Aspergillus flavus (A. flavus) is a postharvest fungus, causing pitaya fruit decay and limiting pitaya value and shelf life. However, safer and more efficient methods for preventing A. flavus contamination for pitaya fruit remain to be investigated. In this study, we successfully proved exogenous Fe2+ could inhibit A. flavus colonization in pitaya fruit and extend pitaya?s shelf life after harvest. Moreover, gel electrophoresis, CD analysis and Raman spectrum tests revealed Fe2+ could more effectively and thoroughly promote conidial death by directly binding to A. flavus DNA. Increased expression of DNA damage repair-related genes after Fe2+ treatment was observed by transcription analysis, which might eventually lead to SOS response in A. flavus. These results indicated Fe2+ could prevent A. flavus infestation on pitaya in a novel, quickly responsive mechanism. Our results shed light on the potential application of Fe2+ in the food industry and provided a more universal antifungal agent against food pathogens. Figure is nr. 2 of the original paper. Fig. 2. Phenotypes of Fe2+ application in pitaya preservation and A. flavus sterilization. Pitaya without any treatment as a control (A); pitaya inoculated with 105 CFU/mL A. flavus spore suspension (B); pitaya inoculated with Fe2+ for the preservation test (C); pitaya inoculated with 105 CFU/mL A. flavus spore suspension and soaked with Fe2+ for the sterilization test (D). All fruit were stored at 25 ? for 7 d. SourceFe2+ protects postharvest pitaya (Hylocereus undulatus britt) from Aspergillus. flavus infection by directly binding its genomic DNALishan Yao Tao, Zhang Shurui, Peng Dan, Xu Zhenbin, Liu Hongbo, Li Liangbin & HuHaizhen MoFood Chemistry: Molecular SciencesVolume 5, 30 December 2022, 100135https://doi.org/10.1016/j.fochms.2022.100135https://www.sciencedirect.com/science/article/pii/S2666566222000636