Effects of sub-lethal concentrations of hexanal and 2-(E)-hexenal on membrane fatty acid composition and volatile compounds of Listeria monocytogenes, Staphylococcus aureus, Salmonella enteritidis and Escherichia coli.
In recent years, the interest in the possible use of natural alternatives to food additives to prevent bacterial and fungal growth has notably increased. Plants and plant products can represent a source of natural alternatives to improve the shelf-life and the safety of food. Some of these compounds, i.e. hexanal, hexanol, 2-(E)-hexenal and 3-(Z)-hexenol, produced throughout the lipoxygenase pathway have important roles in plant defence with a protective action towards microbial proliferation in wounded areas. Otherwise, hexanal and 2-(E)-hexenal have evidenced a marked antimicrobial activity against food spoilage and pathogenic microbial species both in model and real systems. The precise mechanisms of action of all these antimicrobial compounds are not yet clear. Because the usage of these compounds as antimicrobials in foods has to be supported by the comprehension of mechanisms of action of these compounds, the overall purpose of this work was to study the modifications of the cell membrane and volatile compounds of Listeria monocytogenes, Staphylococcus aureus, Salmonella enteritidis and Escherichia coli during the growth in the presence of sub-lethal doses of these two aldehydes. The results obtained evidenced that the tested molecules induced noticeable modifications of the composition of cell membrane and the volatile compounds produced during the growth. Although specific differences in relation to the species considered were identified, 2-(E)-hexenal and hexanal induced a marked increase of some membrane associated fatty acids, both linear and branched fatty acids as well as unsaturated fatty acids, and released free fatty acids.
Dipartimento di Scienze degli Alimenti, Università degli Studi di Bologna, Via Fanin 46, 40127 Bologna, Italy.
Francesca
F
Patrignani
Luciana
L
Iucci
Nicoletta
N
Belletti
Fausto
F
Gardini
M Elisabetta
ME
Guerzoni
Rosalba
R
Lanciotti
D000447:Aldehydes / Q000378:metabolism / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003257:Consumer Product Safety; D004926:Escherichia coli / Q000254:growth & development / Q000378:metabolism; D005232:Fatty Acids, Volatile / Q000096:biosynthesis*; D005519:Food Preservation / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D008089:Listeria monocytogenes / Q000254:growth & development / Q000378:metabolism; D008563:Membrane Lipids / Q000032:analysis* / Q000737:chemistry; D012477:Salmonella enteritidis / Q000254:growth & development / Q000378:metabolism; D052617:Solid Phase Microextraction; D013211:Staphylococcus aureus / Q000254:growth & development / Q000378:metabolism
D000447:Aldehydes; D000900:Anti-Bacterial Agents; D005232:Fatty Acids, Volatile; D008563:Membrane Lipids; C010463:n-hexanal