No abstract

This study evidenced the efficacy of photodynamic inactivation as a novel and promising alternative to bacterial control.

This study evaluated the rose bengal‐ and erythrosine‐mediated photoinactivation against Salmonella Typhimurium and Staphylococcus aureus planktonic and sessile cells using green LED as a light source. The free‐living or 2‐day‐old biofilm cells were treated with different concentrations of the photosensitizing agents and subjected to irradiation. Only 5 min photosensitization with rose bengal at 25 nmol L−1 and 75 μmol L−1 completely eliminated S. aureus and S. Typhimurium planktonic cells, respectively. Erythrosine at 500 nmol L−1 and 5 min of light exposure also reduced S. aureus planktonic cells to undetectable levels. Eradication of S. aureus biofilms was achieved when 500 μmol L−1 of erythrosine or 250 μmol L−1 of rose bengal was combined with 30 min of irradiation. Scanning electron microscopy allowed the observation of morphological changes in planktonic cells and disruption of the biofilm architecture after photodynamic treatment. The overall data demonstrate that rose bengal and erythrosine activated by green LED may be a targeted strategy for controlling foodborne pathogens in both planktonic and sessile states.

No abstract

The reduction in slaughter age with minimum fat and dry aging process improves meat tenderness, however, its shelf‐life in display has not been studied. It was evaluated the sensorial, and the color, lipid oxidation, and visual acceptance in display of dry‐aged beef (0, 14, and 28 days) from young bulls slaughtered with different subcutaneous fat thickness (2.00, 3.00, and 4.00 mm). Meat with 2.00 and 3.00 mm fat had higher acceptability than 4.00 mm (p < .05). Dry aging improved overall acceptability of consumers. Meat with 2.00 and 3.00 mm fat presented higher lightness and lipid oxidation values than 4.00 mm (p < .05) but similar visual acceptance was observed. Dry‐aged beef (14 and 28 days) had lower lightness, but higher redness (p < .05) than not dry aged (0 days). Display reduced color over time, for all dry‐aged treatments (p < .05). Dry aging process increased lipid oxidation but these values were below 2.00 mg/kg of malonaldehyde only in the first day of display. Dry aged for 14 days had similar visual acceptability to not dry‐aged beef until the third day of display (p < .05). Shelf‐life of 0, 14, and 28 days of dry aged was 5.41, 2.55, and 0.23 days. Despite of the increase in lipid oxidation and lightness, the sensorial and display acceptability of meat from young bulls was not prejudiced by the reduction in fat thickness. Beef dry‐aged for 14 days was visually well accepted and could be displayed for 2.55 days without compromising acceptability.