Pomegranate peel extract (PGE) is a new promising natural alternative control substance with large spectrum of activity against wide range of pathogenic microorganisms. In the present study, PGE was firstly investigated as natural antimicrobial against Listeria monocytogenes both in vitro and on fresh-cut fruits. The in vitro results showed quick and strong bactericidal and bacteriostatic activity against five different strains which were almost completely inhibited by the extract. Furthermore, it significantly decreased growth rate and maximum growth of all tested strains. In vivo trials, confirmed a strong antibacterial activity of the extract that significantly reduced the bacterial load on fresh-cut apple, melon and pear and maintained the population at low levels throughout the storage period (7 days). PGE at 12 g/l reduced L. monocytogenes by 1.24, 1.89, and 0.91 log units soon after treatment and by 3.81, 1.53, and 2.99 log units, after 7 days of storage on apple, pear and melon, respectively. This high antibacterial activity could be mainly related to the high content of polyphenols (ellagitannins) in the extract. Overall, results of this study suggest a potential industrial application of PGE to reduce the growth of the pathogenic microorganisms in fresh-cut fruit and ensure a microbial safety in case of contamination.

中文翻译：

---

石榴皮提取物（PGE）在体外和鲜切梨，苹果和甜瓜上减少单核细胞增生李斯特菌的功效

石榴皮提取物（PGE）是一种新的有前途的天然替代控制物质，对多种病原微生物具有广泛的活性。在本研究中，首先研究了PGE作为单核细胞增生李斯特菌的天然抗菌剂无论是在体外还是在鲜切水果上。体外结果显示对五种不同菌株的快速和强大的杀菌和抑菌活性，这些菌株几乎完全被提取物抑制。此外，它显着降低了所有测试菌株的生长速率和最大生长。在体内试验中，证实了提取物具有很强的抗菌活性，可显着降低鲜切苹果，甜瓜和梨上的细菌负荷，并在整个存储期间（7天）保持种群处于低水平。PGE 12 g / l减少单核细胞增生李斯特菌分别在苹果，梨和甜瓜上储存7天后，分别在处理后不久以1.24、1.89和0.91 log单位增加了3.81、1.53和2.99 log单位。这种高抗菌活性可能主要与提取物中多酚（鞣花单宁）的含量高有关。总体而言，这项研究的结果表明，PGE的潜在工业应用可减少鲜切水果中的病原微生物的生长，并在污染的情况下确保微生物的安全性。