Eucalyptus globulus Essential Oil as a Natural Food Preservative: Antioxidant, Antibacterial and Antifungal Properties In Vitro and in a Real Food Matrix (Orangina Fruit Juice)

Mohamed Nadjib Boukhatem,Mehdi Rajabi,Asma Boumaiza,Hanady G Nada,Shaker A Mousa

doi:10.3390/app10165581

Abstract

The potential application of Eucalyptus globulus essential oil (EGEO) as a natural beverage preservative is described in this research. The chemical composition of EGEO was determined using gas chromatography analyses and revealed that the major constituent is 1,8-cineole (94.03% ± 0.23%). The in vitro antioxidant property of EGEO was assessed using different tests. Percentage inhibitions of EGEO were dose-dependent. In addition, EGEO had a better metal ion chelating effect with an IC50 value of 8.43 ± 0.03 mg/mL, compared to ascorbic acid (140.99 ± 3.13 mg/mL). The in vitro antimicrobial effect of EGEO was assessed against 17 food spoilage microorganisms. The diameter of the inhibitory zone (DIZ) ranged from 15 to 85 mm for Gram-positive bacteria and from 10 to 49 mm for yeast strains. Candida albicans, C.parapsilosis and Saccharomyces cerevisiae were the most sensitive fungal species to the EGEO vapor with DIZ varying from 59 to 85 mm. The anti-yeast effectiveness of EGEO alone and in association with heat processing was estimated in a real juice matrix (Orangina fruit juices) in a time-dependent manner. The combination of EGEO-heat treatment (70 °C for 2 min) at different concentrations (0.8 to 4 µL/mL) was effective at reducing S. cerevisiae growth in the fruit juice of Orangina, compared to juice preserved with synthetic preservatives. Current findings suggest EGEO as an effective and potent inhibitor of food spoilage fungi in a real Orangina juice, and might be a potential natural source of preservative for the food industry.

Highlights

Food spoilage by fungi, yeasts and bacteria is a major problem in food production, and it considerably impacts the price and availability of the food [1]
Current data are in accordance with those published by Elaissi et and Goldbeck et al [26], who found that the principal chemical element of Eucalyptus globulus essential oil (EGEO) was eucalyptol
Current findings demonstrated that EGEO can be used with moderate heat action for the food protections of Current findings revealed that EGEO could be used as a possible antifungal and antibacterial agent against foodborne and food spoilage microorganisms

Summary

Introduction

Yeasts and bacteria is a major problem in food production, and it considerably impacts the price and availability of the food [1]. The use of synthetic and chemical antibacterial and antifungal compounds and food preservatives is considered as one of the ancient methods for reducing foodborne pathogens and contamination. The addition of synthetic antioxidant and antimicrobial food preservatives is an active way for storage to slow down food alteration and oxidation [2]. Sci. 2020, 10, 5581 food additives, there is constant pressure from consumers to decrease the quantity of these chemicals in food [3] and deliver minimally processed foodstuffs without compromising food preservation, safety and quality [4]

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