Abstract:

Antimicrobial properties and stability of galactosyl monolaurin were investigated in this study. The minimum
inhibitory concentration (MIC) of galactosyl monolaurin against five bacteria and three fungi from foods were determined
by doubling dilution method. Escherichia coli and Bacillus cereus were used as indicator bacteria to investigate the effects
of temperature, pH, UV irradiation and salt concentration on the stability of galactosyl monolaurin. Results showed that galactosyl
monolaurin could inhibit five tested bacteria and had little or no effect on the growth of three tested fungi. The MIC of galactosyl
monolaurin against Pseudomouas fluorescens was 0.078 mg/mL, and the same MIC value of 0.156 mg/mL was observed against
Escherichia coli, Bacillus subtilis, Bacillus cereus and Staphylococcus aureus. In the pH range of 5 to 8, the antibacterial activity
of galactosyl monolaurin was stable. Temperature and UV irradiation showed little effect on the antimicrobial activity of galactosyl
monolaurin. With increasing NaCl concentration, this antimicrobial activity decreased significantly.

Key words: galactosyl monolaurin, antimicrobial activity, stability