Evaluation of antimicrobial activities of plant aqueous extracts against Salmonella Typhimurium and their application to improve safety of pork meat

• Published in: Scientific reports 2021-11, Vol.11 (1), p.21971-14, Article 21971
• Main Authors: Gavriil, Alkmini, Zilelidou, Evangelia, Papadopoulos, Angelis-Evangelos, Siderakou, Danae, Kasiotis, Konstantinos M., Haroutounian, Serkos A., Gardeli, Chrysavgi, Giannenas, Ilias, Skandamis, Panagiotis N.
• Format: Article
• Language: English
• Subjects: 631/326; 692/499; Animals; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Antimicrobial activity; Antimicrobial agents; By products; Chromatography, High Pressure Liquid - methods; Coatings; Colony Count, Microbial; Corn; Essential oils; Food Safety; Humanities and Social Sciences; Inoculation; Meat; Microbial Sensitivity Tests; multidisciplinary; Oils & fats; Plant extracts; Plant Extracts - chemistry; Plant Extracts - pharmacology; Pork; Pork Meat - microbiology; Purification; Refrigeration; Salmonella; Salmonella Typhimurium; Salmonella typhimurium - drug effects; Salmonella typhimurium - isolation & purification; Science; Science (multidisciplinary); Spectrometry, Mass, Electrospray Ionization - methods; Swine; Tandem Mass Spectrometry - methods; Water - chemistry
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-021-01251-0

Nine odorless laboratory-collected hydro-distilled aqueous extracts (basil, calendula, centrifuged oregano, corn silk, laurel, oregano, rosemary, spearmint, thyme) and one industrial steam-distilled oregano hydrolate acquired as by-products of essential oils purification were screened for their in vitro antimicrobial activity against three Salmonella Typhimurium strains (4/74, FS8, FS115) at 4 and 37 °C. Susceptibility to the extracts was mainly plant- and temperature-dependent, though strain dependent effects were also observed. Industrial oregano hydrolate eliminated strains immediately after inoculation, exhibiting the highest antimicrobial potential. Hydro-distilled extracts eliminated/reduced Salmonella levels during incubation at 4 °C. At 37 °C, oregano, centrifuged oregano, thyme, calendula and basil were bactericidal while spearmint, rosemary and corn silk bacteriostatic. A strain-dependent effect was observed for laurel. The individual or combined effect of marinades and edible coatings prepared of industrial hydrolate and hydro-distilled oregano extracts with or without oregano essential oil (OEO) was tested in pork meat at 4 °C inoculated with FS8 strain. Lower in situ activity was observed compared to in vitro assays. Marinades and edible coatings prepared of industrial oregano hydrolate + OEO were the most efficient in inhibiting pathogen. Marination in oregano extract and subsequent coating with either 50% oregano extract + OEO or water + OEO enhanced the performance of oregano extract. In conclusion, by-products of oregano essential oil purification may be promising alternative antimicrobials to pork meat stored under refrigeration when applied in the context of multiple hurdle approach.