Ben Hsouna Anis, Ben Halima Nihed, Smaoui Slim, Hamdi Naceur
Department of Life Sciences, Faculty of Sciences of Gafsa, Zarroug, 2112, Gafsa, Tunisia.
Biotechnology and Plant Improvement Laboratory, Centre of Biotechnology of Sfax, PO Box 1177, Road Sidi Mansour 6 km, 3018, Sfax, Tunisia.
Lipids Health Dis. 2017 Aug 3;16(1):146. doi: 10.1186/s12944-017-0487-5.
Lemon (Citrus limon) is a flowing plant belonging to the Rutaceae family. Citrus plants constitute one of the main valuable sources of essential oil used in foods and medicinal purposes.
In this study, we assessed chemical composition, antioxidant and antimicrobial activities of C. limon essential oil (ClEO) with its preservative effect against Listeria monocytogenes inoculated in minced beef meat. Gas chromatography/mass spectrometry (GC-MS) was used to identify the major components of the obtained ClEO. The antioxidant activities of this ClEO were determined according to the β-carotene bleaching assay, as well as by 2.2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. For antimicrobial activity, agar well diffusion method was used and the minimum inhibitory concentrations (MICs) as well as the minimum fungicidal concentrations (MFCs) were determined. The in situ effect of the ClEO was evaluated through physicochemical parameters (pH and thiobarbituric acid reactive substances (TBARS), as well as against L. monocytogenes in minced beef meat model.
Twenty one components were identified in the ClEO and the two dominant compounds were limonene (39.74%) and β-Pinene (25.44%). This ClEO displayed an excellent DPPH scavenging ability with an extract concentration providing 50% inhibition (IC) of 15.056 μg/ml and a strong β-carotene bleaching inhibition after 120 min of incubation with an IC of 40.147 μg/ml. The MICs varied from 0.039 to 1.25 mg/ml for Gram positive bacteria and from 0.25 to 2.5 mg/ml for Gram-negative bacteria. The meat preserving potential of ClEO was investigated against L. monocytogenes. ClEO successfully inhibited development of L. monocytogenes in minced beef meat. The application of ClEO at a 0.06 and 0.312 mg/g, may open new promising opportunities for the prevention of contamination from and growth of pathogenic bacteria, particularly L. monocytogenes, during minced beef meat storage at 4 °C. Additionally, during storage period, physicochemical values (pH and TBARS) were higher in control meat than treated meat with ClEO suggesting an efficient antioxidant activity of ClEO.
It was suggested that the ClEO may be a new potential source as natural antimicrobial and antioxidant agents applied in food systems and pharmaceutical industry.
柠檬（Citrus limon）是一种属于芸香科的开花植物。柑橘类植物是用于食品和药用的精油的主要宝贵来源之一。
在本研究中，我们评估了柠檬精油（ClEO）的化学成分、抗氧化和抗菌活性，及其对接种在碎牛肉中的单核细胞增生李斯特菌的防腐效果。采用气相色谱/质谱联用（GC-MS）鉴定所获得的ClEO的主要成分。根据β-胡萝卜素漂白试验以及2,2-二苯基-1-苦基肼（DPPH）自由基清除活性来测定该ClEO的抗氧化活性。对于抗菌活性，采用琼脂扩散法并测定最低抑菌浓度（MIC）以及最低杀菌浓度（MFC）。通过理化参数（pH和硫代巴比妥酸反应性物质（TBARS））以及在碎牛肉模型中针对单核细胞增生李斯特菌来评估ClEO的原位效果。
在ClEO中鉴定出21种成分，两种主要化合物为柠檬烯（39.74%）和β-蒎烯（25.44%）。该ClEO表现出优异的DPPH清除能力，提取物浓度为15.056μg/ml时提供50%抑制率（IC），在孵育120分钟后对β-胡萝卜素漂白有强烈抑制作用，IC为40.147μg/ml。革兰氏阳性菌的MIC范围为0.039至1.25mg/ml，革兰氏阴性菌的MIC范围为0.25至2.5mg/ml。研究了ClEO对碎牛肉中单核细胞增生李斯特菌的保鲜潜力。ClEO成功抑制了碎牛肉中单核细胞增生李斯特菌的生长。以0.06和0.312mg/g的剂量应用ClEO，可能为预防在4°C下储存碎牛肉期间病原菌，特别是单核细胞增生李斯特菌的污染和生长带来新的有前景的机会。此外，在储存期间，对照肉中的理化值（pH和TBARS）高于用ClEO处理的肉，这表明ClEO具有有效的抗氧化活性。
有人提出，ClEO可能是一种新的潜在来源，可作为天然抗菌剂和抗氧化剂应用于食品系统和制药行业。
