Tannin-Rich Fraction from Pomegranate Rind Damages Membrane of Listeria monocytogenes

作者：Guanghui Li, Yunfeng Xu, Xin Wang, Baigang Zhang, Chao Shi, Weisong Zhang, Xiaodong Xia · 发表于：Foodborne Pathogens and Disease · 年份：2014 · DOI：10.1089/fpd.2013.1675 · 被引用次数：55 · 研究领域：Pomegranate: compositions and health benefits、Essential Oils and Antimicrobial Activity、Food Science and Nutritional Studies

Pomegranate rind has been reported to inhibit several foodborne pathogens, and its antimicrobial activity has been attributed mainly to its tannin fraction. This study aimed to investigate the antimicrobial activity of the tannin-rich fraction from pomegranate rind (TFPR) against Listeria monocytogenes and its mechanism of action. The tannin-related components of TFPR were analyzed by high-performance liquid chromatography and liquid chromatography-mass spectrometry, and the minimum inhibitory concentration (MIC) of TFPR was determined using the agar dilution method. Extracellular potassium concentration, the release of cell constituents, intra- and extracellular ATP concentrations, membrane potential, and intracellular pH (pHin) were measured to elucidate a possible antibacterial mechanism. Punicalagin (64.2%, g/g) and ellagic acid (3.1%, g/g) were detected in TFPR, and the MICs of TFPR were determined to be 1.25-5.0 mg/mL for different L. monocytogenes strains. Treatment with TFPR induced a decrease of the intracellular ATP concentration, an increase of the extracellular concentrations of potassium and ATP, and the release of cell constituents. A reduction of pHin and cell membrane hyperpolarization were observed after treatment. Electron microscopic observations showed that the cell membrane structures of L. monocytogenes were apparently impaired by TFPR. It is concluded that TFPR could destroy the integrity of the cell membrane of L. monocytogenes, leading to a loss of ce...