Antifungal, antitoxigenic, and antioxidant activities of the essential oil from laurel ( Laurus nobilis L.): Potential use as wheat preservative

Essential oils (EOs) are widely used in the food industry as natural food preservatives to extend product shelf life and as flavoring agents. The aim of this work was to study the chemical profile of the EO from laurel (Laurus nobilis) and its antifungal, antitoxigenic, and antioxidant activities. The extractive yield of the EO from Algerian laurel was 1.13% being 1,8-cineole the most dominant compound (35.5%) by gas chromatography-mass spectrometry analysis. The values of minimum inhibitory concentration and minimum fungicidal concentration (MFC) against Aspergillus flavus were 1.75 and 2 mg/ml, respectively. The production of aflatoxin B1 was inhibited by EO concentrations between 0.25 mg/ml (15% decrease) and 1.50 mg/ml (86% decrease), and it was totally inhibited at the MFC value. The EO showed a wide antifungal spectrum against other species in a dose-dependent manner. In a food-model study, the L. nobilis EO showed remarkable efficacy in fumigated wheat grains, providing from 51.5% to 76.7% protection against A. flavus during 6-month storage. The L. nobilis EO showed good free radical scavenging activity by DPPH assay (IC₅₀ value of 602 μg/ml) and moderate antioxidant activity in the β-carotene bleaching assay (46% inhibition of linoleic acid oxidation). The conclusions of this study justify future research for the application of EO from laurel as a natural preservative to improve food safety and extend shelf life by controlling spoilage and toxigenic molds as well as oxidative damage.

Keywords: Aspergillus flavus; aflatoxin B1; antifungal activity; antioxidant activity; essential oil; laurel; wheat grains.