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The aim of this study was to determine the chemical composition and antibacterial activity of essential oils (EOs) extracted from local plant by steam distillation from the aerial parts (fresh – dried) of rosemary (Rosmarinus officinalis L.), pistachio (Pistacia lentiscus L.) and thyme (Thymus vulgaris L.). Monoterpenes were identified by GC-MS as main compounds, namely 1,8-cineole (34.5–35 %), α-pinene (36.2–36.6 %) and thymol (42.2–42.1 %). Our results showed that EOs tested had antibacterial effects at different levels, with MICs ranging from 1.56 to 6.25 mg.mL−1. Fresh rosemary EO was synergistic against Pseudomonas aeruginosa ATCC 27,853 when combined with dried rosemary EO and fresh pistachio EO, with MICs half those of oils alone (from 6.25 to 3.12 mg.mL−1). In addition, antagonistic, additive and indifferent effects were recorded at 1 %, 3 % and 93 %, respectively. Our findings provide new data on antimicrobial potential of local plants and possibilities of their use as food preservatives. [ABSTRACT FROM AUTHOR]

An interesting property for many probiotic strains is to exhibit antimicrobial activity against pathogenic microorganisms. Therefore, the antimicrobial activity of the potentially probiotic strain Lactobacillus acidophilus L12 against Escherichia coli, Staphylococcus aureus and Salmonella sp. was examined in vitro through co-culturing of Lactobacillus acidophilus L12 with each of the pathogenic strains for 72 h. When cultured individually, all strains reached a final population always exceeding 1012 cfu/mL. When co-cultured with each of the pathogenic strains Lactobacillus acidophilus L12 population always exceeded 1012 cfu/mL, while the bacterial population of the pathogenic strains was reduced in a strain-specific manner. Lactobacillus acidophilus L12 demonstrated the highest inhibitory activity against the two Staphylococcus aureus strains, followed by the two E. coli strains, and the two Salmonella sp. strains tested. The kinetics of the co-culturing process of Lactobacillus acidophilus L12 with each of the test pathogenic strains was modelled using the logistic curve model. The obtained results show the strong antagonistic activity of the potentially probiotic strain Lactobacillus acidophilus L12, thus making it a promising candidate for inclusion in the composition of probiotic preparations and functional probiotic foods.

The antimicrobial activity of potentially probiotic strains is important for their possible application in the development of successful strategies for bio-preservation of different foods. The antimicrobial activity of the potentially probiotic strain Lactobacillus plantarum L4 against the pathogenic bacteria Salmonella abony; Staphylococcus aureus; Escherichia coli and the phytopathogenic fungi Aspergillus niger and Aspergillus flavus was determined using agar-diffusion assay with wells. Lb. plantarum L4 exhibited high antagonistic activity against all test microorganisms included in the study, which was due not only to the production and accumulation of lactic acid and other organic acids, but also to the production of other bioactive substances. The bioactive substances were then submitted to the action of different enzymes. This allowed to observe that they have protein nature, suggesting that they are likely bacteriocins or bacteriocin-like substances. The substances produced by Lb. plantarum L4 did not lose their antimicrobial activity during heat treatment at temperatures above 100 °С for 15 min and they exhibited high inhibitory activity against the test-microorganisms when pH ranged between 4 and 7. After further examination of the properties of the produced antimicrobial compounds, Lb. plantarum L4 can be used in the development of strategies for bio-preservation of different food products.

Fresh fish is a perishable food in which chemical (namely oxidation) and microbiological degradation result in undesirable odor. Non-processed fish (i.e., raw fish) is increasingly commercialized in packaging systems which are convenient for its retailing and/or which can promote an extension of its shelf-life. Compared to fish sent to its retail unpackaged, fish packaging results in a modification of the gaseous composition of the atmosphere surrounding it. These modifications of atmosphere composition may affect both chemical and microbiological degradation pathways of fish constituents and thereby the volatile organic compounds produced. In addition to monitoring Total Volatile Basic Nitrogen (TVB-N), which is a common indicator to estimate non-processed fish freshness, analytical techniques such as gas chromatography coupled to mass spectrometry or techniques referred to as "electronic nose" allow either the identification of the entire set of these volatile compounds (the volatilome) and/or to selectively monitor some of them, respectively. Interestingly, monitoring these volatile organic compounds along fish storage might allow the identification of early-stage markers of fish alteration. In this context, to provide relevant information for the identification of volatile markers of non-processed packaged fish quality evolution during its storage, the following items have been successively reviewed: (1) inner atmosphere gaseous composition and evolution as a function of fish packaging systems; (2) fish constituents degradation pathways and analytical methods to monitor fish degradation with a focus on volatilome analysis; and (3) the effect of different factors affecting fish preservation (temperature, inner atmosphere composition, application of hurdle technology) on volatilome composition. [ABSTRACT FROM AUTHOR]

The antioxidant and the lipase and the angiotensin‐converting enzyme (ACE) inhibitory properties of camel lactoferrin and its hydrolysates elaborated with four proteolytic enzymes (trypsin, α‐chymotrypsin, pancreatin and papain) were assessed. Lactoferrin was purified from camel colostrum using cation exchange chromatography. Camel lactoferrin hydrolysates showed different degrees of hydrolysis, reverse phase‐HPLC profiles and molecular weight distributions, reflecting heterogeneity in terms of polarity and molecular weight of the generated peptides. Camel lactoferrin hydrolysates exhibited higher antioxidant, lipase and ACE inhibitory activities than native lactoferrin. Pancreatin‐generated hydrolysates showed the highest lipase inhibitory activity (48.1%), while papain‐generated hydrolysates presented the greatest ACE inhibitory activity (89.14%). [ABSTRACT FROM AUTHOR]