Enhancement of Nisin Production by Lactococcus lactis subsp. lactis.

Lactococcus lactis subsp lactis BSA (L. lactis BSA) was isolated from a commercial fermented product (BSA Food Ingredients, Montreal, Canada) containing mixed bacteria that are used as starter for food fermentation. In order to increase the bacteriocin production by L.

Combined effects of marinating and γ-irradiation in ensuring safety, protection of nutritional value and increase in shelf-life of ready-to-cook meat for immunocompromised patients.

The aim of this study was to evaluate the effect of combining marinating and γ-irradiation at doses of 1, 1.5 and 3kGy on Escherichia coli O157:H7, Salmonella typhimurium and Clostridium sporogenes in raw meat packed under vacuum and stored at 4°C and to estimate its safety and shelf-life. Further, the effect of combined treatments on sensorial, nutritional values (lipid oxidation, concentration of thiamin and riboflavin) and color was evaluated.

Antimicrobial effects of marine algal extracts and cyanobacterial pure compounds against five foodborne pathogens.

The marine environment is a proven source of structurally complex and biologically active compounds. In this study, the antimicrobial effects of a small collection of marine-derived extracts and isolates, were evaluated against 5 foodborne pathogens using a broth dilution assay. Results demonstrated that algal extracts from Padina and Ulva species and cyanobacterial compounds antillatoxin B, laxaphycins A, B and B3, isomalyngamide A, and malyngamides C, I and J showed antimicrobial activity against Gram positive foodborne pathogens (Listeria monocytogenes, Bacillus cereus and Staphylococcus aureus) at low concentrations (⩽ 500 μg/ml).

Development of a model describing the inhibitory effect of selected preservatives on the growth of Listeria monocytogenes in a meat model system.

The objective of this study was to evaluate the impact of seven independent factors consisting of sodium nitrite, pH, sodium chloride, sodium acetate, sodium lactate syrup, calcium propionate and a blend of nisin and hop alpha acids on the growth rate of Listeria monocytogenes in ham as a model of ready-to-eat (RTE) meat products. A central composite consisted of seven factors mentioned above was designed and the response surface methodology was applied for creating a mathematic model to predict the growth rate of L. monocytogenes in RTE meat products.

In vitro evaluation of antimicrobial activities of various commercial essential oils, oleoresin and pure compounds against food pathogens and application in ham.

The purpose of this research was to evaluate the application of commercially available essential oils (EOs) and oleoresins to control bacterial pathogens for ready to eat food. In this study, sixty seven commercial EOs, oleoresins (ORs) and pure compounds were used to evaluate in vitro their antimicrobial activity against six food pathogens. These products were first screened for their antimicrobial activity using disk diffusion assay.

Response of Bacillus cereus vegetative cells after exposure to repetitive sublethal radiation processing in combination with nisin.

The present study evaluated the response of Bacillus cereus LSPQ 2872 vegetative cells, following exposure to single and repetitive sublethal γ-radiation treatment at 1 kGy alone or in combination with nisin at its maximum tolerated concentration, in BHI broth supplemented with 0.5% glucose. Results showed that B.

Modification and characterization of biodegradable methylcellulose films with trimethylolpropane trimethacrylate (TMPTMA) by γ radiation: effect of nanocrystalline cellulose.

Methylcellulose (MC)-based films were prepared by solution casting from its 1% aqueous suspension containing 0.25% glycerol. Trimethylolpropane trimethacrylate (TMPTMA) monomer (0.

Response of Bacillus cereus to gamma-irradiation in combination with carvacrol or mild heat treatment.

Carvacrol and mild heat treatment were tested for their efficiency to increase the radiosensitivity of Bacillus cereus in broth. The bacterium was treated with gamma-irradiation alone or in combination with carvacrol at its minimal inhibitory concentration or mild heat treatment for 10 min at 45 degrees C. The effects of this combination of treatments were studied on various parameters: the bacterial viability, the modifications of the cell morphology with scanning electron microscopy (SEM), the cellular fatty acids composition of the membrane quantified by gas chromatography, the intracellular and extracellular adenosine 5'-triphosphate (ATP) concentrations, and the DNA degradation.

Production and properties of nanocellulose-reinforced methylcellulose-based biodegradable films.

Methylcellulose (MC)-based films were prepared by casting from its 1% aqueous solution containing 0.5% vegetable oil, 0.25% glycerol, and 0.

Changes in membrane fatty acids and murein composition of Bacillus cereus and Salmonella Typhi induced by gamma irradiation treatment.

This present study was carried out to evaluate the effects of gamma irradiation on the fatty acids (FA) and mureins composition of two different radiotolerant bacteria. Bacillus cereus LSPQ 2872 and Salmonella Typhi ATCC 19430 were used for this study. The bacterial strains were treated with a sublethal radiation dose of 1kGy to cause a cellular damage.