Bioactive Hexane Extracts from Piper aduncum and Xylopia aromatica Against Bacterial Strains which Cause Food Poisoning

Plants and their extracts have been used as natural antimicrobial agents in food products as a strategy to mitigate food contamination. Therefore, this study aimed to determine the chemical composition of hexane extracts from Piper aduncum leaves and inflorescences (HE-PL and HE-PI, respectively) and from Xylopia aromatica leaves (HE-XA) by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC-FID). Antibacterial activities of HE-PL, HE-PI and HE-XA were evaluated in terms of their minimum inhibitory concentration (MIC = µg/mL) and minimum bactericidal concentration (MBC = µg/mL) values by the broth microdilution method in 96-well microplates. Major constituents found in HE-PL were germacrene B (33.1%), valencene (14.5%), β -cadinene (9.1%) and α -humulene (8.1%) while the ones found in HE-PI were sesquiterpenes caryophyllene oxide (20.5%), spathulenol (15.2%) and germacrene B (9.7%). Spathulenol (41.2%), α -copaene (16.6%) and β -phellandrene (7.9%) were the major constituents in HE-XA. Since the extracts under study exhibited excellent MIC and MBC values, they showed high bioactive potential against Bacillus cereus , Salmonella typhimurium , Escherichia coli , Brochothrix thermosphacta , Clostridium botulinum and Pseudomonas fluorescens . Besides, this study showed, for the first time, that both P. aduncum and X. aromatica have antimicrobial properties against these microorganisms, a fact that reveals their biotechnological potential in food preservation.