Inactivation of Bacillus cereus by Cyclamen Aldehyde Nanoemulsion: Mechanisms and Application in Ready-to-Eat Braised Beef

Cyclamen aldehyde (CA), a widely used fragrance ingredient, was fabricated using ultrasound-assisted emulsification. The CA nanoemulsion displayed favorable characteristics, including a mean particle size of 160.87 nm, a low homogeneous droplet distribution of 0.27, and excellent storage stability. It demonstrated potent antibacterial activity against Bacillus cereus, with minimum inhibitory concentrations (MIC) of 0.12 mg/mL against vegetative cells and 0.23 mg/mL against spores. The nanoemulsion disrupted cell membrane permeability, induced leakage of intracellular proteins and nucleic acids, altered membrane potential, and elevated intracellular reactive oxygen species levels. It also suppressed bacterial motility, inhibited, and removed mature B. cereus biofilm. Additionally, the nanoemulsion impeded spore germination, altered spore hydrophobicity, and stimulated dipicolinic acid (DPA) release. Applied to braised beef, the nanoemulsion significantly inhibited vegetative cell counts and extended shelf-life. These findings highlight the robust anti-B. cereus efficacy of CA nanoemulsion, providing a theoretical foundation for its use in controlling foodborne pathogens.