Insights into the antifungal and antiaflatoxin efficacy of Citrus limon leaf essential oil against Aspergillus flavus based on multi-omics

Citrus limon leaf essential oil (LLEO) inhibits Aspergillus flavus growth. • (R)-(+)-citronellal is the major antifungal component of LLEO. • LLEO induces membrane damage, disrupts metabolism and modulates oxidative stress. • LLEO reduces aflatoxin B 1 accumulation in postharvest Arecae Semen and peanuts. Agricultural food commodities are highly susceptible to fungal contamination and mycotoxin accumulation, with aflatoxin B 1 (AFB 1 ), produced by Aspergillus species being the most toxic. Given the urgent demand for eco-friendly treatments, this study investigated the antifungal and antiaflatoxin activities of Citrus limon leaf essential oil (LLEO) against Aspergillus flavus , as well as its underlying mechanisms. LLEO significantly inhibited A. flavus growth and AFB 1 accumulation. SPME-GC-MS analysis identified (R)-(+)-citronellal as the major antifungal component of LLEO, with other minor constituents potentially contributing synergistically. Mechanistically, LLEO reduced ergosterol content, modulated oxidative stress, and disrupted energy metabolism. Integrative multi-omics analysis further revealed that LLEO suppressed mycelial growth and aflatoxin production by modulating primary metabolism, peroxisome function, and AF synthesis pathways. Notably, LLEO effectively inhibited A. flavus infection in Arecae Semen and peanuts when applied as vapors in the headspace of sealed samples. Collectively, these findings demonstrate that LLEO is a promising natural preservative for the postharvest control and safety of agricultural commodities.