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

Abstract

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.

Treatment of Gout with TCM Using Turmeric and Corn Silk: A Concise Review Article and Pharmacology Network Analysis

“…"Southern Yunnan Materia Medica" records its treatment of swelling and pain [46]. Modern research shows that corn silk contains sugars, flavonoids, mineral elements, volatile oils, alkaloids, amino acids, and other chemical components that have anti-oxidant [47], antibacterial [48], antitumor [49], blood sugar-lowering [50], and other pharmacological effects. A recent study found that corn silk can reduce serum uric acid levels by 26.69% (p < 0.05) and serum xanthine oxidase (XO) activity by 11.29% (p < 0.05) [51].…”

Bactericidal activity of Piper betle L. extract against antibiotic resistant Salmonella spp. isolated from pig farms in Southern Thailand

“…It has been reported that clinical isolates of Salmonella spp. was naturally resistant to ampicillin, chloramphenicol, and sulphamethoxazole/trimethoprim (Gong et al, 2022). However, some study demonstrated that the clinical isolates of Salmonella spp.…”

“…In attempt to overcome the multi-drug resistant Salmonella spp., natural products based on their secondary metabolites have been used as an alternative treatment against the pathogen (Naz et al, 2022). The aqueous extracts of oregano, thyme, calendula, and basil exhibited bactericidal activity against S. Typhimurium (Gavriil et al, 2021). In the present study, we focused on Piper betle L. leaf extract, known as a betel vine.…”

In silico evaluation of phytochemicals present in Bambusa polymorpha and Citrus limon extracts against Salmonella enteric Typhimurium combined with in vitro antimicrobial and acidic stress responsive studies

“…S . Typhimurium is one of the most common serovars isolated from pork (Gavriil et al, 2021). Despite the efforts undertaken to maintain good hygienic practices throughout the production of meat, complete prevention of microbial contamination has not attained yet.…”

“…S. Typhimurium outbreaks have become more common around the globe and their prevalence has been highly associated with the animal products such as eggs, pork, and poultry. S. Typhimurium is one of the most common serovars isolated from pork (Gavriil et al, 2021). Despite the efforts undertaken to maintain good hygienic practices throughout the production of meat, complete prevention of microbial contamination has not attained yet.…”