PurposeThis study aimed to evaluate the antimicrobial activity of the aqueous extract from jaboticaba skin against important foodborne bacteria and fungi and its stability.Design/methodology/approachJaboticaba skin aqueous extract (at ratio of 10 g L-1) was tested against Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus and Escherichia coli. Stability of the anti-staphylococcal activity, total phenolics, monomeric anthocyanins, tannins, phenolic acid content were measured and statistically correlated.FindingsThe residue extract inhibited L.monocytogenes, S.aureus, B.cereus and E.coli growth but was not effective against fungi and was stable to the thermal treatments, remaining with its inhibitory activity against S.aureus. When stored for 14 days at 25 °C with an incidence of light, there was a reduction in the antibacterial activity and in the phenolic compounds. The change in pH slightly changed polyphenolic content profile, and the exposure to papain and bromelain did not affect the antimicrobial activity. Results showed strong correlation between anti-staphylococcal activity, the presence of polyphenols and anthocyanins, meanwhile moderate correlation with phenolic acids content in the extract.Originality/valueBiopreservatives are a great trend in food microbiology. The present work shows deeper information about the utilization of jaboticaba skin as antimicrobial agent and its stability, which is not found in the current literature.

Jaboticaba peels are an important source of health-benefit and antimicrobial compounds. The present work aims to evaluate concentration of polyphenolics and the mode of action of aqueous extract from jaboticaba peels against Staphylococcus aureus and Escherichia coli. Jaboticaba peel extract showed minimum inhibitory concentration and minimum bactericidal concentration against S. aureus of 5.1 g L-1 and 10.1 g L-1, respectively; meanwhile, against E. coli the parameters were 2.0 g L-1 and 3.4 g L-1. Kinetics of viable cell counts indicated a bacteriolytic action against both bacteria and Scanning Electron Microscopy (SEM) showed that jaboticaba peel extract causes subtle morphological changes in bacterial cells. Concentration of total polyphenols in the extract was 1535.04±36.05 mg of gallic acid equivalent (GAE) mL-1, monomeric anthocyanins was 14.52 ± 0.98 mg of cyanidin 3-glucoside mL-1, condensed tannins was 0.49 ± 0.05 mg of epicatechin equivalent mL-1 and phenolic acids was 80.04 ± 4.11 mg of caffeic acid equivalent (CAE) mL-1, which have demonstrated well-documented antibacterial activity. In conclusion, jaboticaba peel aqueous extract may be an interesting natural preservative to control Gram-positive and Gram-negative bacteria growth when interacting with the bacteria cell wall.

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