Histamine and tyramine production by bacteria isolated from spoiled sardine (Sardina pilchardus)

Bacterial strains (32) from spoiled sardine were isolated and investigated for their ability to produce histamine and tyramine in histidine and tyrosine decarboxylase broth, respectively by a rapid highperformance liquid chromatography (HPLC) method. The predominant microflora of sardine consisted of the genera Enterobacteriaceae, Pseudomonas, Chryseobacterium, Vibrio, Photobacterium, and Stenotrophomonas. In histidine-enriched broth, the highest levels of histamine were observed in Proteus mirabilis (5201.95 mg/L), followed by Enterobacter cloacae (2333.99 mg/L), whilst the lowest histamine accumulation was found for Kluyvera spp. and Listeria monocytogenes at the level of 0.38 and 0.45 mg/L, respectively. However, Pseudomonas oryzihabitans, Chryseobacterium indologenus and Vibrio vulnificus showed the highest accumulation of tyramine in tyrosine decarboxylase broth with values of 1648.85, 774.20 and 187.96 mg/L, respectively. Serratia liquefaciens produced more than 1000 mg/L putrescine in both enrichment broths, although Serratia rulnidace did not have the ability to produce amines (except for dopamine, serotonin and agmatine) in tyrosine decarboxylase broth. The study results show that P. mirabilis and  Enterobacter cloacae, which were dominantly found in spoiled sardine, were strong amine producers.Keywords: Biogenic amines, histamine, tyramine, spoilage, sardineAfrican Journal of Biotechnology Vol. 12(21), pp. 3288-329

In vitro determination of the antifungal activity of Artemisia campestris essential oil from Algeria

The chemical composition of the essential oil isolated from the aerial parts of Artemisia campestris from Algeria and its antifungal activity against 10 filamentous fungal strains were investigated. The A. campestris essential oil was obtained in a yield of 0.71% (v/w). The major constituents of the oil were ?-pinene (18.65%), ß-pinene (16.78%), ß-myrcene (17.34%), and germacrene D (10.34%). Our study showed that A. campestris essential oil was a potent antifungal agent against some pathogenic fungal species. Fusarium graminearum was the most sensitive strain to A. campestris essential oil with minimal inhibitory concentration and minimal fungicidal concentration values of 1.25 µL/mL (v/v). The essential oil also exhibited a strong fungicidal activity against the tested fungi, except for Penicillium citrinum, P. viridicatum, and Aspergillus niger (MFC >20 µL/mL). Our findings suggested the application of A. campestris essential oil as a biofungicide in order to reduce the dependence on synthetic fungicides and ensure food safety and quality. © Taylor & Francis Group, LLC

In vitro study of the antifungal activity of essential oils obtained from Mentha spicata, Thymus vulgaris, and Laurus nobilis

PubMedID: 27697030Background: The aim of this study was to determine the antifungal activity of the essential oils isolated from three aromatic plants against 13 filamentous fungal strains. Methods: The major constituents of Mentha spicata, Thymus vulgaris, and Laurus nobilis essential oils were carvone (52.2%), linalool (78.1%), and 1,8-cineole (45.6%), respectively. There are also some patents suggesting the use of essential oils as natural and safe alternatives to fungicides for plant protection. Results: In the present work, M. spicata essential oil exhibited the strongest activity against all tested fungi in which Fusarium graminearum, F.moniliforme, and Penicillium expansum were the most sensitive to mint oil with lower minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) values of 2.5 µL mL-1 (v/v). Thymus vulgaris essential oil was less active compared to the oil of M. spicata. Aspergillus ochraceus was the most sensitive strain to thyme oil with MIC and MFC values of 2.5 and 5 µL mL-1, respectively. Thymus vulgaris essential oil also exhibited a moderate fungicidal effect against the tested fungi, except for A. Niger (MFC >20 µL mL-1). L. nobilis essential oil showed a similar antifungal activity with thyme oil in which A. parasiticus was the most resistant strain to this oil (MFC >20 µL mL-1). Conclusion: Our findings suggested the use of these essential oils as alternatives to synthetic fungicides in order to prevent pre-and post-harvest infections and ensure product safety. © 2016 Bentham Science Publishers

Chemical composition and antifungal activity of Anacyclus valentinus essential oil from Algeria

The chemical composition of Anacyclus valentinus essential oil from Algeria was determined and its antifungal effect in vitro toward 7 toxigenic fungal strains was evaluated. Essential oil yield of 0.13% (v/w) was obtained from the aerial parts of A. valentinus using hydrodistillation. The GC/MS analysis identified 29 components of which ?-3-carene (31%), spathulenol (14.2%), decanoic acid (5.5%), ?-cadinene (4.4%), anethole (3.4%) and aromadendrene (3.3%) were the major compounds of this oil. The results of the antifungal activity showed that the most sensitive fungal strains to A. valentinus oil were Fusarium graminearum, Aspergillus parasiticus, and Penicillium expansum with lower minimal fungicidal concentration (MFC) of 1.25 µl/ml (v/v). The oil also had a strong fungicidal effect against A. flavus and F. moniliforme at a MFC value of 2.5 µl/ml, while the oil concentration of 10 µl/ml was needed to show a fungicidal activity against A. ochraceus and P. citrinum. This study suggested that A. valentinus oil is a potential candidate to be used as a safe biocontrol agent to prevent food crops from fungal diseases and improve product quality and safety. © 2018 Elsevier Lt

Simple Approximation of the Magnetic Induction Inside High Voltage Overhead Transmission Lines

With the development of electrical power transmission networks, are resulted the increase and continuous consumption of various power production sources, this is what requires the large quantities of energy construction. The increased demand in electric power employment has generated an raised of operating voltage for transmission lines (HV and VHV). The high voltage overhead transmission lines create electric and magnetic fields, and therefore have elevated serious concern questions about their possible potential effects in human body and environmental great associated with the resulting higher levels of electromagnetic fields strength around these power lines. The accurate evaluation of extremely low frequency electromagnetic fields influences produced by the high voltage overhead power lines on human health and the environment are well very known and analysed in several research works and simulation study projects. In this paper we precise examine and present a methodology for plot the lateral profile of magnetic field distribution in close a three-phase overhead transmission line in single circuit flat horizontal configuration at height 1m above the ground level, In order show the essentials factors affecting in the magnetic fields intensity under and in the vicinity of high voltage overhead transmission line in any point of space surface and ground plane, the analytique calculation results of the lateral profile of magnetic flux density behaviour are obtained by program MATLAB software, which makes it possible better analyser and easy represent the transverse profile of the magnetic field around electric power transmission lines, the numerique simulation results are based in image method and the superposition theorem

Effect of Mentha spicata L. and Artemisia campestris extracts on the shelf life and quality of vacuum-packed refrigerated sardine (Sardina pilchardus) fillets

PubMedID: 24112571The present study investigated the effects of ethanolic extracts obtained from Mentha spicata and Artemisia campestris on the shelf life and the quality of vacuum-packed sardine fillets stored at 3 ± 1°C for a period of 21 days. The three groups were tested were VC, control group; VM, group treated with 1% mint extract; and VA, group treated with 1% artemisia extract. The observed shelf life of sardine fillets was 10 days for control samples, whereas the combination of vacuum packaging with mint and artemisia extracts extended the product's shelf life to 17 days. Among the chemical indices determined, the thiobarbituric acid-reactive substances values were significantly lower in VM samples. Total volatile base nitrogen was maintained at low levels in VA samples until 17 days of chilled storage. Results of aerobic plate counts and coliform counts showed the existence of a reduced growth in VA group, whereas lactic acid bacteria did not show a significant difference among groups. Natural extract treatments combined with vacuum packaging showed lower microbiological and chemical indices, indicating that the presence of phenolic compounds in mint and artemisia extracts and the removal of oxygen in the pack retarded lipid oxidation and reduced the growth of microorganisms, which resulted in preventing spoilage and extending the product's shelf life. Copyright © International Association for Food Protection

Effect of Natural Extracts (Mentha spicataL. and Artemisia campestris) on Biogenic Amine Formation of Sardine Vacuum-Packed and Refrigerated (Sardina pilchardus) Fillets

Ethanolic extracts from mint and artemisia were applied on vacuum-packed sardine fillets in order to investigate their effects on biogenic amine formation during 21 days at 3±1C. Three different groups were tested: control group (without ethanolic extracts), T1 (mint extract - 1% w/v) and T2 (artemisia extract - 1% w/v). Natural extract treatments combined with vacuum packaging resulted in a significant shelf life extension of the sardine fillets of 7 days. Treated groups had lower (P<0.05) histamine, tyramine and cadaverine contents than control samples. Mint extract was the most effective in decreasing biogenic amine production in fish muscle, while the artemisia extract treatment contributed to maintain histamine-forming bacteria at low levels until day 17 of chilled storage. Our findings suggest the application of mint and artemisia extracts in fish industry since they improve food safety and increase product's shelf life without altering the sensory properties of fish. © 2015 Wiley Periodicals, Inc

Assessment of biogenic amines profile in ciders from the Central Europe region as affected by storage time

The aim of the research was the assessment of 8 biogenic amines occurrence (BA) in ciders. Forty samples with ethanol content ≤4.5% v/v (LC; low alcohol content) and 34 samples with ethanol content &gt; 4.5% v/v (HC; high alcohol content) manufactured in the Central Europe region were tested. The cider samples were immediately analyzed after purchase and at the end of the best before date. The most abundant BA across all ciders was tyramine, followed by putrescine and cadaverine (p &lt; 0.05). Samples reported low levels of tryptamine, spermidine, spermine, histamine and phenylethylamine. No cider at the end of the best before date had a sum of BA below &lt;5 mg l−1. Moreover, 67% of the samples at the beginning of the storage period and 47% of the ciders after the best before date presented a total BA content in the range of 5–20 mg l−1. A total number of 14% of the samples immediately after purchase and 31% of samples at the end of the best before date showed a BA concentration in the range of 20–50 mg l−1. The BA content of 16 samples was &gt;50 mg l−1 at the end of the best before date. However, one LC cider and two HC products displayed a BA sum of nearly 120 mg l−1. In general, higher concentrations of tyramine, cadaverine and putrescine were detected in LC samples. All in all, with the prolonging of storage the BA concentration increased. © 2021 Elsevier LtdGrant Agency of the Czech Republic (GACR)Grant Agency of the Czech Republic [17 - 09594S]; Ministry of Defence of the Czech RepublicGrantová Agentura České Republiky, GA ČR: 17˗09594S; Ministerstvo Obrany České Republiky, MOČ