Antibacterial activity of a hexahydro‐β‐acids/methyl‐β‐cyclodextrin inclusion complex against bacteria related to foodborne illness

Abstract

AbstractIn this study, we investigated the antibacterial activity of hexahydro‐β‐acids/methyl‐β‐cyclodextrin inclusion complex (HBA/M‐β‐CD) and researched its antibacterial mechanism against Staphylococcus aureus and Enterobacter sakazakii. The result showed that bacteria had different sensitivities to HBA/M‐β‐CD with diameters of inhibition zones ranging from 7.8 ± 0.5 to 14.8 ± 0.7 mm and minimum inhibitory concentration (MIC) values from 16.25 to 65.00 μg/mL. Among these bacteria, S. aureus (G(+)) and E. sakazakii (G(−)) were most sensitive to HBA/M‐β‐CD, and MIC value is 16.25 and 32.50 μg/mL, respectively. Also, HBA/M‐β‐CD had potential inhibition effect on the bacterial growth of S. aureus and E. sakazakii. Moreover, the treatment with HBA/M‐β‐CD led to a release of cell contents into the culture medium, indicating damage to the plasma membrane. Scanning electron microscopy revealed permeabilization of S. aureus membranes, and shrinkage and roughening of E. sakazakii cells. HBA/M‐β‐CD also reduced the activity of succinate dehydrogenase (SDH) in bacterial cultures, indicating that HBA/M‐β‐CD interfere key enzyme metabolism.Practical ApplicationsIn the actual food system of western‐style ham sausage, HBA/M‐β‐CD revealed a great antibacterial effect to control the total bacteria count, and could stabilize the pH value. The result provided the theoretical and practical basis for the application of HBA/M‐β‐CD in foods.