Black Cumin (Nigella sativa) as a Natural Food Preservative: GC-MS Profiling and Antimicrobial Activity against Spoilage Microorganisms

Background

Nigella sativa, also referred as black cumin and described as the miraculous herb, exhibits many medicinal and pharmacological properties.

Objectives

This research focused on the antimicrobial effectiveness of different N. sativa Seeds (NSS) extracts against spoilage microbes and phytochemical analysis of seed extract via Gas Chromatography-Mass Spectrometry (GC-MS).

Materials and Methods

Using agar well diffusion method, acetone, hexane, ethanolic and aqueous extracts of N. sativa seeds were examined against spoilage causing bacteria and fungi. Extracts showing highest inhibitory activity was subjected to phytochemical screening via GC-MS analysis.

Results

Both aqueous and ethanolic extract of NSS exhibited significant inhibitory activity against spoilage bacteria and fungi at a concentration of 10 mg/mL, with MIC value 0.5 mg/mL for spoilage fungi and 2.5 mg/mL for spoilage bacteria. Phytochemical screening using Gas Chromatography-Mass Spectrometry (GC-MS) revealed nineteen compounds in the ethanolic extract and seven compounds in the aqueous extract. The identified compounds contributing to antimicrobial activity include thymoquinone, 2,4-Di-tert-butylphenol, 2-methyl-5-(1-methylethyl) phenol, n-Hexadecanoic acid and p-Cymene-2,5-diol.

Conclusion

N. sativa seeds contain a rich profile of bioactive compounds (e.g., thymoquinone, ethyl oleate, 2,4-Di-tert-butylphenol, etc.) and exhibits effective antimicrobial activity against food spoilage microorganisms. These findings indicate its potential application as a natural preservative in food industry.