Antifungal Activity of Essential Oil Compounds (Geraniol and Citral) and Inhibitory Mechanisms on Grain Pathogens ( Aspergillus flavus and Aspergillus ochraceus )

• Published in: Molecules (Basel, Switzerland) Vol. 23; no. 9; p. 2108
• Main Authors: Tang, Xi, Shao, Ye-Lin, Tang, Ya-Jie, Zhou, Wen-Wen
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 22-08-2018; MDPI
• Subjects: Antifungal activity; Antifungal Agents - chemistry; Antifungal Agents - pharmacology; Apoptosis; Aspergillus; Aspergillus flavus - drug effects; Aspergillus flavus - genetics; Aspergillus flavus - ultrastructure; Aspergillus ochraceus - drug effects; Aspergillus ochraceus - genetics; Aspergillus ochraceus - ultrastructure; Catabolism; Cell death; Cell Membrane Permeability - drug effects; Cell membranes; Chemical pollution; Citral; Contamination; Cytology; Developing countries; Ecosystem assessment; Edible Grain - microbiology; Environmental changes; Essential oils; Food contamination & poisoning; Fumigants; Fungi; Fungicides; Gene expression; Gene Expression Profiling; geraniol; Grain; Grain storage; Health risks; Intracellular; LDCs; Microbial Sensitivity Tests; modified atmosphere packaging; Monoterpenes - chemistry; Necrosis; Oils, Volatile - chemistry; Oils, Volatile - pharmacology; Organic chemistry; Oxidative phosphorylation; Packaging; Pathogens; Phosphorylation; Pollution control; reactive oxygen species; Reactive Oxygen Species - metabolism; relative electric conductivity; Respiration; Respiratory rate; Scanning electron microscopy; Seeds; Shelf life; Terpenes - chemistry; modified atmosphere packaging; Aspergillus; citral; geraniol; reactive oxygen species; relative electric conductivity; antifungal activity; gene expression
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules23092108

The grain contamination by
spp. has been a serious issue. This study exhibited the excellent antifungal effects of the essential oil compounds (EOCs) geraniol and citral against common grain pathogens (
and
) in vitro and in situ. The inhibitory mechanisms were also evaluated from the perspective of cell membrane permeability, reactive oxygen species (ROS) generation, and
spp. growth-related gene expression. Meanwhile, the combined effects of EOCs in the vapor phase and modified atmosphere packaging (MAP) were examined to find an alternative preservation method for controlling
spp. The results indicated that citral exhibited the antifungal activity mainly by downregulating the sporulation- and growth-related genes for both pathogens. Geraniol displayed inhibitory effectiveness against
predominantly by inducing the intracellular ROS accumulation and showed toxicity against
principally by changing cell membrane permeability. Furthermore, the synthetic effects of EOCs and MAP (75% CO₂ and 25% N₂) induced better grain quality than the current commercial fumigant AlP. These findings reveal that EOCs have potential to be a novel grain preservative for further application.