Stable Concentrated Emulsions of the 1-Monoglyceride of Capric Acid (Monocaprin) with Microbicidal Activities against the Food-Borne Bacteria Campylobacter jejuni , Salmonella spp., and Escherichia coli

Abstract

Of 11 fatty acids and monoglycerides tested against Campylobacter jejuni, the 1-monoglyceride of capric acid (monocaprin) was the most active in killing the bacterium. Various monocaprin-in-water emulsions were prepared which were stable after storage at room temperature for many months and which retained their microbicidal activity. A procedure was developed to manufacture up to 500 ml of 200 mM preconcentrated emulsions of monocaprin in tap water. The concentrates were clear and remained stable for at least 12 months. They were active against C. jejuni upon 160-to 200-fold dilution in tap water and caused a >6-to 7-log 10 reduction in viable bacterial count in 1 min at room temperature. The addition of 0.8% Tween 40 to the concentrates as an emulsifying agent did not change the microbicidal activity. Emulsions of monocaprin killed a variety of Campylobacter isolates from humans and poultry and also killed strains of Campylobacter coli and Campylobacter lari, indicating a broad anticampylobacter activity. Emulsions of 1.25 mM monocaprin in citrate-lactate buffer at pH 4 to 5 caused a >6-to 7-log 10 reduction in viable bacterial counts of Salmonella spp. and Escherichia coli in 10 min. C. jejuni was also more susceptible to monocaprin emulsions at low pH. The addition of 5 and 10 mM monocaprin emulsions to Campylobacter-spiked chicken feed significantly reduced the bacterial contamination. These results are discussed in view of the possible utilization of monocaprin emulsions in controlling the spread of food-borne bacteria from poultry to humans.

Antimicrobial activities of medium-chain fatty acids and monoacylglycerols on Cronobacter sakazakii DBM 3157^T and Cronobacter malonaticus DBM

“…Salmonella species were susceptible to caproic acid (Van Immerseel et al 2004) and caprylic acid (Skřivanová et al 2004). Thormar et al (2006) found that capric acid and monocaprin were more efficient against Campylobacter jejuni as compared with caprylic acid and monocaprylin, this observation having been confirmed by Molatová et al (2010). Depending on the monocaprylin concentrations and the temperatures examined, increasing temperature enhanced the bactericidal activity of monocaprylin, which can be partially explained by an increase in solubility.…”

Therapeutic Supplementation of Caprylic Acid in Feed Reduces Campylobacter jejuni Colonization in Broiler Chicks

“…Fatty acids, especially medium chain fatty acids, were found to have antimicrobial properties for a wide range of microorganisms (2,3,16,19,24,27). Recently, Thormar and coworkers (26) reported that monocaprin, the monoglyceride of capric acid, was effective in killing significant populations of C. jejuni in chicken feed. Caprylic acid is a medium chain fatty acid with eight carbons naturally found in breast milk, bovine milk, and coconut oil (12,13,16).…”

Divergence of a strain of Pseudomonas aeruginosa during an outbreak of ovine mastitis

“…In contrast, capric acid has been shown to have antimicrobial properties against other Gram-negative bacteria, including Campylobacter jejuni, Salmonella spp. and Escherichia coli (Thormar et al, 2006).…”