Food Microbiology, Wageningen University & Research, Wageningen, The Netherlands; Food Chemistry, Wageningen University & Research, Wageningen, The Netherlands.
Food Chemistry, Wageningen University & Research, Wageningen, The Netherlands.
Food Res Int. 2024 Sep;191:114613. doi: 10.1016/j.foodres.2024.114613. Epub 2024 Jun 14.
Glabridin is an antimicrobial compound which can be extracted from plants, such as liquorice (Glycyrrhiza glabra) roots. Although its activity against foodborne pathogens and spoilage microorganisms has already been reported, the investigation of potential applications as a surface disinfectant is still largely unexplored. Hence, this study evaluated the disinfectant efficacy of glabridin against Listeria monocytogenes. The activity of glabridin was first tested in vitro in a nutrient-rich medium against eight strains of L. monocytogenes, including food isolates and the model strain EGDe. The tested strains showed similar susceptibility with minimal inhibitory and bactericidal concentrations of 12.5 µg/mL and 25 µg/mL, respectively. Subsequently, L. monocytogenes L6, FBR17 and EGDe were selected to assess the efficacy of glabridin against dried cells (according to the European standard EN 13697:2015 + A1:2019) and biofilm cells on stainless steel surfaces. Moreover, the impact of food residual organic matter was investigated using skim milk, cantaloupe and smoked salmon solution as soiling components. Our results showed that applying 200 µg/mL of glabridin resulted in a substantial reduction (>3 log) of dried and biofilm cells of L. monocytogenes in standard conditions (i.e. low level of residual organic matter). Cantaloupe soiling components slightly reduced the activity of glabridin, while the efficacy of glabridin when tested with salmon and skim milk residuals was substantially affected. Comparative analysis using standardized protein contents provided evidence that the type of food matrices and type of proteins may impact the activity of glabridin as a disinfectant. Overall, this study showed low strain variability for the activity of glabridin against L. monocytogenes and shed light on the possible application of this natural antimicrobial compound as a surface disinfectant.
甘草素是一种从植物中提取的抗菌化合物，例如甘草（Glycyrrhiza glabra）根。虽然已经报道了其对食源性病原体和腐败微生物的活性，但作为表面消毒剂的潜在应用的研究仍在很大程度上未被探索。因此，本研究评估了甘草素对李斯特菌的消毒效果。首先在富含营养的培养基中测试了甘草素的体外活性，针对八种李斯特菌菌株，包括食品分离株和模型菌株 EGDe。测试菌株的敏感性相似，最小抑菌浓度和杀菌浓度分别为 12.5μg/mL 和 25μg/mL。随后，选择李斯特菌 L6、FBR17 和 EGDe 来评估甘草素对干燥细胞（根据欧洲标准 EN 13697:2015+A1:2019）和不锈钢表面生物膜细胞的功效。此外，还使用脱脂乳、哈密瓜和熏三文鱼溶液作为污垢成分研究了食物残留有机物的影响。我们的结果表明，在标准条件下（即低残留有机物水平），应用 200μg/mL 的甘草素可使李斯特菌的干燥细胞和生物膜细胞大量减少（>3 对数）。哈密瓜污垢成分略微降低了甘草素的活性，而用三文鱼和脱脂乳残余物测试时，甘草素的功效受到了很大影响。使用标准化蛋白质含量进行的比较分析提供了证据，表明食物基质的类型和蛋白质的类型可能会影响甘草素作为消毒剂的活性。总体而言，这项研究表明甘草素对李斯特菌的活性具有低菌株变异性，并阐明了这种天然抗菌化合物作为表面消毒剂的可能应用。
