Trond Møretrø, Bjørn C. T. Schirmer, Even Heir, Solveig Langsrud
Short communication: In situ evaluation of citric acid powder to control Listeria monocytogenes on floors in meat processing plants
Kurzmitteilung: In situ Untersuchung der Verwendung von Zitronensäurepulver zur Kontrolle von Listeria monocytogenes auf Fussböden in der Fleischwarenindustrie
Several guidelines for control of L. monocytogenes in food processing environments recommend the addition of citric acid powder to floors. However, documentation of the effect of this advice on L. monocytogenes in the food industry is not available in scientific literature. In the current study, the effect of addition of citric acid powder to five floors and a floor gutter, where water was observed to accumulate, on the occurrence of L. monocytogenes and total bacterial numbers were tested in situ in two meat processing plants. Overall, starting with addition of citric acid lead to a reduction of L. monocytogenes positive floors from 59 % to 13 %. Listeria monocytogenes was eradicated from all floor areas, with the exception of a floor that was positive in three out of four samplings in the citric acid test period. The total bacterial counts were on average lower in the period with addition of citric acid than in the control period. In the current study it was shown that addition of citric acid powder to floors where water tend to accumulate, can be effective for control of L. monocytogenes.
Sunčica Kocić-Tanackov, Nevena Blagojev, Irena Suturović, Gordana Dimić, Jelena Pejin, Vladimir Tomović, Branislav Šojić, Jovo Savanović, Snežana Kravić, Neđeljko Karabasil
Antibacterial activity of essential oils against Escherichia coli, Salmonella enterica and Listeria monocytogenes
Antibakterielle Aktivität ätherischer Öle gegen Escherichia coli, Salmonella enterica und Listeria monocytogenes
Antimicrobial potential of six essential oils (EOs) (basil, ginger, hyssop, caraway, juniper, and sage) against three food-borne bacterial pathogens, commonly found as meat product contaminants (Escherichia coli, Salmonella enterica and Listeria monocytogenes), using disc diffusion and broth microdilution methods, was evaluated. The EOs composition was determined by gas chromatography-mass spectrometry (GC-MS) technique. Dominant compounds in analyzed EOs were: estragole (in basil EO), cis-pinocamphone (in hyssop EO), α-pinene (in juniper EO), α-thujone (in sage EO), carvone (in caraway EO) and curcumene (in ginger EO). Basil EO inhibited growth of all tested bacteria (disc diffusion method). Tested concentrations of ginger EO lacked bactericidal activity. Only basil EO showed inhibitory effect on L. monocytogenes growth. Compared to all tested EOs, caraway EO had the highest antibacterial activity on E. coli and S. enterica.
Minimal inhibitory concentration (MIC) of basil and sage EOs was 56.8 µl/mL for all tested bacteria. Hyssop, caraway, and juniper EOs were inhibitory at concentration of 113.6 µl/mL on all tested bacterial species. MIC of ginger EO was 113.6 µL/mL for E. coli and L. monocytogenes and 227.3 µL/mL for S. enterica. Minimal bactericidal concentration (MBC) of basil and sage EOs was 113.6 µl/mL for all investigated bacteria. MBC of hyssop, caraway, and juniper EOs was 227.3 µl/mL for all investigation bacteria. MBC of ginger EO was 227.3 µL/mL for E. coli and L. monocytogenes and 454.5 µL/mL for S. enterica. Tested EOs have a great potential as natural antibacterial preservative in food.
Mehmet Musa Özcan, Senay Simsek
Characteristics of Myrtle (Myrtus communis L.) Fruit and Oils
Eigenschaften von Myrte (Myrtus communis L.) Beeren und Öle
In this study, chemical analysis, amino acids, sugar pofile, fatty acid composition and mineral contents of white and black myrtle (Myrtus communis L.) fruits were determined. The crude protein and oil contents of white and black myrtle fruits were determined between 5.99 and 5.45 % to 8.31 and 6.17 % respectively. In addition, total phenol, flavonoid and anthocyanin contents of white and black fruits were determined between 4253 and 4060 mg gallic acid equivalent (GAE)/g, 94.4 and 121.1 mg catechol equivalent (CE)/g, and 0.096 and 1.667 mmol/g, respectively. Aspartic acid contents of white and black myrtle fruits were determined as 0.50 and 0.45 % respectively. In addition, the highest glutamic acid and arginin were found in white myrtle fruits. Fructose and glucose contents of white and black myrtle fruits were reported as 11.26 and 11.53 % to 13.02 and 13.74 % respectively. Linoleic, palmitic, and oleic acid contents of white and black myrtle fruit oils were determined as 72.48 and 68.34 %, 9.99 and 10.43 % to 8.52 and 9.02 % respectively. P, K, Ca, and Mg contents of black and white myrtle fruits were measured as 1335.10 and 1165.15 mg/kg to 2714.16 and 2631.04 mg/kg, 191.13 and 245.28 mg/kg to 837.86 and 720.38 mg/kg respectively. In conclusion, myrtle fruits were found to be important sources of nutrients and essential elements.