Daidai Flower Essential Oil as a Multifunctional Natural Agent: Chemical Profile, Antimicrobial Activity, Preliminary Insecticidal Potential, and Improved Microbiological Quality of Fresh Arugula During Refrigerated Storage.

This study evaluates the potential of daidai flower essential oil (DFEO) (Citrus aurantium var. daidai) as a natural preservative for fresh leafy vegetables. The chemical composition of DFEO was determined by gas chromatography coupled with mass spectrometry (GC-MS), revealing a neroli-type profile dominated by linalool (42.8%), limonene (19.9%), and linalyl acetate (15.3%). The tested batch of DFEO exhibited broad-spectrum antimicrobial activity, with Gram-positive bacteria showing the highest susceptibility. In situ experiments in model food systems confirmed concentration-dependent antimicrobial effects, with inhibition values reaching up to 89.47%. The application of DFEO in combination with vacuum packaging significantly improved the microbiological quality of fresh arugula during refrigerated storage (4°C, 14 days), reducing coliform bacteria by 1.26 log CFU/g compared with untreated controls. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis of culture-dependent bacterial isolates revealed a dominance of Pseudomonas spp., which are key contributors to spoilage of leafy vegetables. Although DFEO also demonstrated insecticidal activity against stored-product pests, its primary relevance lies in its antimicrobial efficacy in food systems. These findings demonstrate that DFEO has potential as a natural preservative for fresh produce, particularly when combined with vacuum packaging, contributing to improved microbiological quality of minimally processed vegetables during refrigerated storage.