Antifungal, aflatoxin inhibition and antioxidant activity of Callistemon lanceolatus (Sm.) Sweet essential oil and its major component 1,8-cineole against fungal isolates from chickpea seeds

The present investigation reports the extent of molds and aflatoxin contamination to Avarodhi, Kabuli, Pusa 256, Radha and Samrat varieties of chickpea seeds. The study also examines the chemical composition of Callistemon lanceolatus (Sm.) Sweet essential oil and its antifungal, antiaflatoxin and antioxidant activity. During standardization of chemical profile, a total of 8 compounds constituting 0.862 mg/mL of oil composition were analyzed by GC-MS analysis where 1,8-cineole was recorded as a major component (0.56 mg/mL). The antifungal activity of EO and 1,8-cineole was evaluated by contact assay on Czapek's dox agar. The EO (0.227-0.908 mg/mL) and 1,8-cineole (0.918 mg/mL) showed remarkable antifungal effect against all the fungal isolates of chickpea. Their minimal inhibitory (MIC) and fungicidal (MFC) concentrations for Aspergillus flavus were lower than those of the prevalent systemic fungicide Nystatin. Aflatoxin B1 (AFB1) production by NKD-208 isolates of A. flavus was strongly inhibited even at the lower fungistatic concentration of EO and 1,8-cineole.There was no adverse effect of EO treatment on chickpea seed germination suggesting its non-phytotoxic nature. Based on the findings of present investigation, C. lanceolatus essential oil may be recommended as botanical preservative for the enhancement of shelf life of food items in- view of the adverse effect of synthetic preservatives and its strong antifungal, aflatoxin inhibition and antioxidant activity.

► The study explores the molds and aflatoxin contamination of chickpea seeds. ► Antifungal, antiaflatoxin activity of Callistemon lanceolatus essential oil. ► Antioxidant efficacy of Callistemon lanceolatus EO. ► Chemical characterization of Callistemon lanceolatus EO. ► Recommendation of Callistemon EO as plant based food preservative.