Assessing the Levisticum officinale Koch. essential oil as a novel preservative for stored chia seeds (Salvia hispanica L.) with emphasis on probable mechanism of action

The present study was undertaken to explore the inhibitory effect of Levisticum officinale Koch. essential oil ( L off EO) on the growth and aflatoxin B 1 secretion by Aspergillus flavus (AF-LHP-SH1, aflatoxigenic strain) causing deterioration of stored chia seeds ( Salvia hispanica ). The chemical profile analysis of L off EO by GC-MS analysis revealed the presence of α-terpinyl acetate (26.03 %) as a major component followed by terpineol (24.03 %) and citronellal (24.03 %). Results on antifungal and antiaflatoxigenic activity indicated that L off EO at 2.0 and 1.75 μL/mL caused complete inhibition of growth and aflatoxin B 1 production, respectively. Antifungal toxicity of L off EO was strongly correlated with the inhibition of ergosterol content, leakage of cellular ions, and disintegration of membrane permeability. Reduction in cellular methylglyoxal by L off EO indicated a novel antiaflatoxigenic mechanism of action. The L off EO showed moderate free radical quenching activity in DPPH assay (IC 50 = 26.10 μL/mL) and exhibited remarkable inhibitory efficacy against lipid peroxidation of chia seeds. In addition, L off EO presented strong in situ antiaflatoxigenic efficacy, and exhibited non-phytotoxic nature, acceptable sensory characteristics, and favorable safety profile (LD 50 = 19786.59 μL/kg), which recommends its practical utilization as a novel and safe preservative to improve the shelf life of stored chia seeds from fungal infestation and aflatoxin B 1 contamination.