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

Abstract

In 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 Applications In 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.

Properties of novel chitosan incorporated with hexahydro‐β‐acids edible films and its effect on shelf life of pork

“…The TBC of pork packed with CH‐0.2% HBA and CH‐0.3% HBA films was fewer than that on day 0 as both CH and HBA have been observed to possess excellent antibacterial activity; in particular, the effect of HBA against Gram‐positive bacteria was obviously better than that against Gram‐negative bacteria. HBA acted on the cell membrane to cause cell membrane shrinkage or disruption to varying degrees, resulting in loss of intracellular nucleic acids, proteins, and other substances, thereby inhibiting bacterial growth (Mohamed et al., 2013; Xu & Liu, 2018; Zhao, Zhao, & Liu, 2019). The CH–HBA film swells in the presence of the meat sample, and HBA is released from the edible film on the sample surface, which prevents fresh meat from being contaminated by bacteria.…”