Screening the efficacy of extracts of different spices in inhibiting the growth of foodborne bacterial isolates

Abstract

Owing to the presence of a diverse group of phytochemicals, spices could be potential sources of antibacterial and antioxidant agents. The present investigation was aimed to determine and compare the antimicrobial activities of different spices. A total of 5 spices including cardamom (Seeds, Elettaria cardamomum), cinnamon (Barks, Cinnamomum verum), clove (Flower buds, Syzygium aromaticum), Indian bay leaf or Tejpat (Dried leaves, Cinnamomum tamala), and cumin (Seeds, Cuminum cyminum) were collected. Different extracts (crude, aqueous, ethanolic, and methanolic) of spices were prepared and examined for antimicrobial activity against previously isolated foodborne bacterial isolates. Extracts from the tested spices showed significant inhibitory effects (mostly with >10 mm mean zone of inhibition) as revealed by the agar well diffusion technique. Clove among the tested spices was found to be the prominent one in eliminating foodborne pathogens. Methanolic extracts followed by ethanolic extracts were determined to be most effective against the bacterial isolates when the relative effectivity of different extracts was compared. The frequently encountered minimal inhibitory and bactericidal concentrations of the spices were 12 and 24 mg/mL, respectively. All the spice extracts showed considerable antimicrobial traits which validate their potential and applicability as natural food preservatives and decontaminants.