Table 2.

Antibacterial and antifungal activities of citral.

Microorganism	Dose (MIC)	Effect	Ref.
Bacteria
V. parahaemolyticus	0.125 mg/mL	Inhibited bacterial growth, causing damage to bacterial membrane and cell wall.	[47]
S. aureus DMST 4745 S. aureus S. agalactiae B. cereus E. coli	0.62–1.25 μL/mL 0.62–1.25 μL/mL 0.31–0.62 μL/mL 0.15 μL/mL 1.25–2.5 μL/mL	Citral possessed bacteriostatic and bactericidal actions at different concentrations.	[48]
E. coli MG1655	300 μL/L	It inactivated at least 2.5 log10 cycles of exponentially growing cells in 3 h under aerobic conditions.	[49]
L. monocytogenes S. aureus E. coli	200 µL/mL 500 µL/mL 500 µL/mL	Growth inhibition.	[50]
L. monocytogenes L. innocua	0.125 mL/mL 0.125 mL/mL	Microbial growth of both Listeria species was reduced by almost 2 log10 CFU/mL.	[51]
L. innocua L. monocytogenes	100 µL/mL	Citral in the culture medium of both bacteria provided a reduction of bacitracin from 32 µg/mL to 4 µg/mL, and the colistin changed from 96 and 128 µg/mL for L. monocytogenes and L. innocua, respectively, to 16 µg/mL, for both species.	[52]
Salmonella Typhimurium	3.1 mM	Citral at subinhibitory concentrations (1, 2, and 3 mM) could induce bacterial adaptation and acquire tolerance to inactivation processes.	[53]
Fungi
B. dothidea P. macrospore B. cinerea	0.2 μL/mL 0.2 μL/mL 0.4 μL/mL	At 0.4 μL/mL, citral entirely inhibited the growth of all the tested fungi. When concentration reached 0.2 μL/mL, citral inhibited the growth of B. dothidea best, followed by P. macrospore and B. cinerea.	[54]
C. sakazakii	0.8 mg/mL	Growth inhibition and cell damage.	[55]
	3600 μM	Concentrations below 225 μM (1/16 MIC) exhibited no inhibition against C. sakazakii ATCC 29544.
Penicillium roqueforti	0.17 mg/mL	Citral combination with eugenol damaged the cell membrane, caused a collapse of mitochondria, and inhibited energy production.	[16]
Penicillium digitatum	2.0 or 4.0 μL/mL	Citral altered the mitochondrial morphology, led to the leakage of ATP, and showed an inhibition of the TCA pathway of P. digitatum cells.	[56]
S. cerevisiae	2.0 mM	MIC: Results showed that yeast cells treated with 2 mM citral reached a 95% reduction in CFU/mL.	[57]
Zygosaccharomyces rouxii.	0.188 μL/mL	The minimum fungicidal concentration was 0.375 μL/mL.	[58]
Candida albicans	64 µg/mL	The minimum fungicidal concentration was 256 µg/mL. The MIC and the MFC of citral required only 4 h of exposure to effectively inhibit 99.9% of the inoculum.	[59]
Aspegillus niger	0.23 mg/mL	The combination of citral and eugenol had a synergistic inhibitory effect on A. niger.	[16]

ATP: adenosine triphosphate; TCA: tricarboxylic acid cycle; MIC: minimal inhibitory concentration; MFC: minimal fungicidal concentration.