Microbiological Quality And Safety Of Selected Spices, And Their Anti-Microbial Activity On Food Borne Pathogens In Hawa Galan District, Oromia Region

Abstract

Spices are essential components of cuisines since ancient times. These are used in minute amounts to impart flavor, and aroma in food preparation to improve their palatability. The present study was performed to detect the presence of contaminating microorganisms in three commonly available spices samples (Red pepper, Curcuma longa and Ginger) collected from different areas of Hawa Galan district, Ethiopia and to assess their antimicrobial activity of their extract against selected food borne pathogens. Cross sectional and experimental study design were used. Sixty (60) samples of three different spices were collected. This study took the time from August 2017 to September 2019. The mean microbial count of Staphylococcus was detected as 4.03±0.011logcfu/g. Staphylococcus was found in ginger samples only. the mean microbial count of Coliform showed as 4.07±0.15log cfu/g. the mean microbial count of Enterobacteriaceae spp was 6.29±0.014logcfu/g. The range of mean total aerobic mesophilic bacterial count was 6.03±0.014log cfu/g to 6.32±0.56log cfu/g. all samples showed a high fungal load that was ranged from 6.02±0.03logcfu to 6.36±0.01log cfu/g. Antibacterial activity of Red pepper, Curcuma longa and Ginger samples was demonstrated against three bacterial references (Escherichia coli, Salmonella typhimurium, staphylococcus aureus) and one fungi (yeast Candida albican). Different extraction solvents (methanol, Chloroform, and Petroleum ether) were used and extracts were examined against the strains. The % extract yield of the spices ranged from 1.6gm to 9.2gm per 100gm of spices dry weight. Agar disc diffusion assay for antimicrobial activity yielded the inhibitory zone of 7.2 to 23 mm diameter for Red pepper, 8 to 18.5 mm diameter for ginger and 8 to 19 mm diameter for Turmeric extract indicating that Red pepper was the most effective spice in inhibiting the microbial growth. The MIC of individual extracts was 25 mg/ml against most of the tested microorganisms.