Chemically characterized Mentha cardiaca L. essential oil as plant based preservative in view of efficacy against biodeteriorating fungi of dry fruits, aflatoxin secretion, lipid peroxidation and safety profile assessment

- Severity of fungal contamination in selected dry fruits.
- Level of Aflatoxin B1contamination in selected dry fruits.
- Chemical profiling of Mentha cardiaca EO.
- Mentha cardiaca EO against fungi and Aflatoxin B1 production.
- Mode of action, antioxidant activity and safety profile of Mentha cardiaca EO.

The study reports Mentha cardiaca essential oil (EO) as plant based preservative against fungal and aflatoxin contamination of stored dry fruits. Mycoflora analysis of the dry fruits revealed Aspergillus favus LHP-PV-1 as the most aflatoxigenic isolate with highest Aflatoxin B1 content. M. cardiaca EO showed broad fungitoxic spectrum inhibiting the tested moulds contaminating dry fruits. It's minimum inhibitory concentration (MIC), minimum aflatoxin inhibitory concentration (MAIC) and minimum fungicidal concentration (MFC) against A. favus LHP-PV-1 were recorded to be 1.25, 1.0 and 2.25 µL/mL respectively. The EO caused decrease in ergosterol content and enhanced leakage of Ca2+, K+ and Mg2+ ions from treated fungal cells, depicting fungal plasma membrane as the site of antifungal action. The EO showed promising DPPH free radical scavenging activity (IC50 value:15.89 µL/mL) and favourable safety profile with LD50 value (7133.70 mg/kg body wt.) when estimated through acute oral toxicity on mice. Carvone (61.62%) was recorded as the major component of the oil during chemical characterisation through GC-MS. Based on strong antifungal, antiaflatoxigenic and antioxidant potential, the chemically characterised M. cardiaca EO may be recommended as safe plant based preservative and shelf life enhancer of food items. This is the first report on antifungal and antiaflatoxigenic activity of M. cardiaca EO.

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