Antioxidant capacity and antibacterial activity of some phyto-spices against some bacterial isolates of foods origin

Abstract

Spices that are mostly of plant origin are used in the preparation of almost all processed food to enhance palatability, tastiness, sweetness, and its overall acceptability, without taking into consideration of its medicinal values. The study was conducted to determine the antioxidant capacity and antibacterial activity of the extracts ofAllium sativum,Syzygium aromaticum, andZingiber officinale against some bacterial isolates of foods origin including Bacillus cereus, Escherichia coli,Salmonella typhi,Shigella dysentriae,andStaphylococcus aureus. Bacterial isolates of food origin were collected from the laboratory unit of the Department of Microbiology, Kano University of Science and Technology, Wudil. Antioxidant capacity of the extracts used was determined using 2,2-diphenylpicrylhydrazyl (DPPH) assay while agar disc diffusion techniques were used in the determination of the antibacterial activity. Results show that extracts of the spices exhibited a strong antioxidants capacity that ranges from 89.5% to 97.5% at high concentrations of the extracts with methanol extracts being the most active. Methanolic extracts shows zone of inhibition ranging from 16.45mm to 5.26mm while that of aqueous extracts were 10.32mm to 4.32mm. Meanwhile isolates of E. coli and S. aureus were the most sensitive with 16.45 and 15.32. This study concluded that the antibacterial effect of methanolic extract of Allium sativum extract was stronger in comparison, followed by Syzygium aromaticum and Zingiber officinale against five test bacteria isolated of food origin. Therefore, this study revealed that spices produced using Allium sativum, Syzygium aromaticum and Zingiber officinale have an antibacterial property and can be used for food preservation.

Keywords

• antibacterial activity
• antioxidant capacity
• methanolic extracts
• spices