Inhibitory effects and membrane damage caused to fish spoilage bacteria by cinnamon bark (Cinnamomum tamala) oil

There is increasing concern regarding the negative effects of synthetic preservatives utilized by the food industry and a demand to replace these synthetic preservatives with natural products by consumers. Thus, the goal of this study was to introduce antimicrobial activity and investigate the underlying mechanism of cinnamon bark oil against common fish spoilage bacteria (Pseudomonas jessenii, Aeromonas veronii, and Shewanella putrefaciens). Cinnamon bark oil exhibited strong antimicrobial activity against tested bacteria, where S. putrefaciens was the most sensitive bacteria, followed by A. veronii and P. jessenii. Tested bacteria cells appeared to undergo lysis after cinnamon bark oil treatment. GC-MS analysis revealed that cinnamaldehyde (85.78%) and diethyl malonate (7.30%) were the major components of cinnamon bark oil. Diethyl malonate had no significant influence on tested bacteria, according to OD260nm results. However, cinnamon bark oil and cinnamaldehyde damaged the macromolecules in cell membranes of tested bacteria, according to FT-IR analysis. Additionally, SDS-PAGE results revealed that cinnamon bark oil and cinnamaldehyde damaged specific membrane proteins of tested bacteria. Collectively, these findings confirm that cinnamon bark oil could be an alternative to synthetic additives used in food preservation, especially in regards to the growth inhibition of S. putrefaciens, A. veronii, and P. jessenii.