Abstract

P. Rattanachaikunsopon* and P. Phumkhachorn

Shallot (Allium ascalonicum L.) oil was studied for its major diallyl sulfide content and its antimicrobial activity against food-borne pathogenic bacteria including Bacillus cereus, Camplobacter jejuni, Escherichia coli O157:H7, Listeria monocytgenes, Salmonella enterica, Staphylococcus aureus, and Vibrio cholerae. The oil had a very low concentration of diallyl monosulfides (1.59%) in comparison with the other diallyl sulfides (24.66% for diallyl disulfide, 16.08% for diallyl trisulfide, and 10.88% for diallyl tetrasulfide). Shallot oil and all four major diallyl sulfides inhibited all of the test bacteria. Among them, E. coli O157:H7 and B. cereus was the most and the least sensitive strains, respectively. The oil had a bacteriocidal effect on C. jejuni, E. coli O157:H7, L. monocytgenes, S. aureus and V. cholerae but had a bacteriostatic effect on B. cereus and S. enterica.