Anti-listerial properties of garlic shoot juice at growth and morphology of Listeria monocytogenes

Abstract

The anti-listerial effect of garlic shoot juice (GSJ) was investigated against the four strains of Listeria monocytogenes ATCC 19116, 19118, 19166 and 15313. Various concentrations of (1%, 2.5% and 5%) were used and applied for 0, 4, 7, 10 and 14 days at 4 °C and 0, 6, 12, 18 and 24 h at 37 °C. 5% GSJ showed the strongest anti-listerial effect of 3–4 log cfu/ml against all the bacterial strains tested as compared to control at 37 °C. At 4 °C, 2.5% GSJ showed a strong growth inhibitory effect of about 2–3 log cfu/ml against all the bacterial strains when compared to control after 14 days, and 5% GSJ rather decreased the number of bacterial cell when compared to initial polulation and showed general lysis of cytoplasm, lysis of cell wall and cellular swelling, and on scanning electron microscopy (SEM) observation, strain L. monocytogenes ATCC 19118 showed swelling, partially distorted shape, pore formation and empty cell formation inside the cell.