Chemical Composition, Biological Action and Use of Zingiber officinale Essential Oil as an Antimicrobial Agent in Minimally Processed Beetroot Inoculated With Bacillus subtilis

Abstract

A significant challenge faced by food producers is ensuring the delivery of safe, high-quality food that remains natural. One promising solution is replacing synthetic chemicals in food formulations with natural alternatives. This approach helps to reduce the dependence on artificial additives. Research focused on natural food preservatives, particularly those derived from plant-based sources with functional properties such as spices, has gained considerable momentum. Among these, the essential oil of Zingiber officinalis (ZOEO) stands out as a potential antimicrobial agent. The purpose of our study was to analyze the chemical composition of this essential oil, assess its antimicrobial properties in vitro, and evaluate its effectiveness against Bacillus subtilis. Through GC–MS analysis, 42 volatile compounds in ZOEO were identified. Among them, the major constituents included α-zingiberene (33.5%), ar-curcumene (14.8%), β-bisabolene (13.6%), and β-sesquiphellandrene (11.9%). For antimicrobial testing, the disc diffusion method was employed, with B. subtilis demonstrating an inhibition zone of 17.67 mm. The minimum inhibitory concentrations (MIC) were determined as MIC₅₀ of 0.97 mg/mL and MIC₉₀ of 1.07 mg/mL. Next, we investigated the antimicrobial impact of ZOEO on B. subtilis inoculated on vacuum-packed beetroot and subjected to sous vide cooking. The results indicated that the combination of ZOEO and sous vide treatment significantly inhibited B. subtilis, offering a promising method to enhance the shelf life of beetroot. Additionally, based on MALDI-TOF MS Biotyper identification of isolates from beetroot samples, the predominant bacterial species were identified as Rahnella aquatilis and Pantoea agglomerans.