RESUMEN
In the present study, selected pathogenic (Salmonella Typhimurium, Escherichia coli, Pseudomonas aeruginosa, Listeria monocytogenes, Bacillus cereus, and Staphylococcus aureus) and nonpathogenic (Pseudomonas fragi, Pseudomonas fluorescens, Brochothrix thermosphacta, Bacillus subtilis, Lactiplantibacillus plantarum, and Leuconostoc mesenteroides) bacteria were subjected in vitro in cold atmospheric pressure plasma (CAPP) treatment for up to 15 min and the changes in the surviving microbial population were determined. Plasma treatments were carried out by a plasma jet device, operating with argon (Ar) as carrier gas under constant flow (4.0 L/min) at a frequency of 1 MHz and an electrical voltage of 2-6 kV. Microbial inactivation data were modelled using linear and nonlinear (Geeraerd, Weibull) models, through which the corresponding kinetic parameters were calculated. After 15 min of exposure to plasma radiation, the total reduction in the bacterial populations was 2.12 log10 CFU mL-1 for P. fragi, 1.77 log10 CFU mL-1 for P. fluorescens, 2.30 log10 CFU mL-1 for B. thermosphacta, 1.58 log10 CFU mL-1 for B. subtilis, 1.31 log10 CFU mL-1 for L. plantarum, 3.80 log10 CFU mL-1 for L. mesenteroides (highest reduction observed), 1.12 log10 CFU mL-1 for S. Typhimurium, 1.18 log10 CFU mL-1 for E. coli, 1.43 log10 CFU mL-1 for L. monocytogenes, 1.32 log10 CFU mL-1 for B. cereus, 0.88 log10 CFU mL-1 for S. aureus, and 0.73 log10 CFU mL-1 for P. aeruginosa. The results showed a higher reduction in the population of nonpathogenic microorganisms compared to pathogens. The relatively small decrease in the inactivation of bacteria indicates that parameter optimization is necessary to be considered to improve the efficacy of the treatment.
RESUMEN
In-package cold atmospheric plasma (CAP) processing, which refers to the generation of CAP inside a sealed package, enables a local disinfecting reaction, allowing no post-process contamination and extending the shelf-life (SL) of perishable food products, such as fresh fish. In the present study, four in-package CAP treatments, differing in frequency and processing time, were applied on fresh gilthead seabream (Sparus aurata) fillets, prepacked in low-permeability pouches. Fish SL was evaluated during isothermal storage at 2°C, whereas untreated packaged fillets were used as control samples. The SL assessment of the fish fillets was based on microbial enumeration of total aerobic mesophilic count (TMC), total aerobic psychrotrophic count (TPC), Pseudomonas spp., Enterobacteriaceae, and lactic acid bacteria (LAB), pH measurement, determination of color and texture parameters, lipid oxidation, total volatile basic nitrogen (TVB-N) measurement, and sensory evaluation. All CAP treatments were effective against microbial inhibition in fish fillets, especially regarding TMC, TPC, and Pseudomonas spp., resulting in maximum reduction of 1.49, 1.24, and 1.43 log CFU/g, respectively, compared to the control samples after 16 days of storage. However, minor effect was observed against Enterobacteriaceae and no effect against LAB. CAP processing did not affect the color and texture parameters of fish fillets, and TVB-N production was slightly reduced in CAP-treated samples; however, lipid oxidation was accelerated, especially at the more intense processing conditions, by a maximum of 75.5%. The results of the study indicated that in-package CAP processing could be effectively applied for inhibiting spoilage during refrigerated storage and extending SL of fresh fish fillets. PRACTICAL APPLICATION: In-package cold atmospheric plasma (CAP) processing was tested on gilthead seabream fillets, a highly perishable product with high commercial potential if its shelf-life can be extended through minimal processing. The food industry could benefit from in-package CAP technology as it is a cost effective nonthermal processing method while preventing post-processing contamination of the products. Although in-package CAP processing has not been extensively tested on fish, this study examined the quality and shelf-life of a highly perishable fish species, and the results could be further used as a reference for processing optimization of the CAP treatments.
Asunto(s)
Microbiología de Alimentos , Embalaje de Alimentos , Conservación de Alimentos , Almacenamiento de Alimentos , Gases em Plasma , Dorada , Alimentos Marinos , Animales , Dorada/microbiología , Gases em Plasma/farmacología , Embalaje de Alimentos/métodos , Almacenamiento de Alimentos/métodos , Conservación de Alimentos/métodos , Alimentos Marinos/microbiología , Alimentos Marinos/análisis , Microbiología de Alimentos/métodos , Recuento de Colonia Microbiana , Pseudomonas , Gusto , Manipulación de Alimentos/métodos , HumanosRESUMEN
A pseudoaneurysm or false aneurysm is the result of the disruption of the vessel wall and the formation of a hematoma in communication with the vascular lumen, restrained by perivascular connective tissue. Intracranial pseudoaneurysms represent a rare entity mainly because of trauma, iatrogenic causes, infectious disease, radiation exposure, connective tissue disease and sometimes spontaneous occurrence. We present a 35-year-old female patient with a history of multiple low-grade glioma debulking surgeries. During the last procedure, laceration of the left middle cerebral artery (MCA) occurred with diffuse subarachnoid hemorrhage. Imaging studies showed the formation of a pseudoaneurysm of the left MCA which was successfully treated with the implantation of a flow diverter across the lesion neck and excellent mid- to long- term results. Flow diverter implantation may be a promising technique for the therapeutic management of cerebral pseudoaneurysms.
RESUMEN
The current study aimed to explore the effects of mild processing for shelf-life extension on the raw an-d cooked quality of gilthead seabream fillets stored at 2 °C. Control and Treated (via osmotic dehydration) fillets were sampled at the beginning (D1), middle (D5) and end (D7) of commercial shelf life. The raw quality was evaluated via the quality index method (QIM), microbial measurements and for D1 through tetrad discrimination testing. The cooked quality was evaluated for the same samples via sensory descriptive analyses with a trained panel. The tetrad results indicated similar characteristics between treatments for raw fillets on D1 and a 29% shelf-life extension for Treated fillets vs. the Control ones, defined by Quality Index Method and microbial measurements. The raw quality was reflected in the cooked quality of the tissue, with the Treated fillets exhibiting less intense spoilage-related sensory attributes as well as enhanced or retained freshness-related attributes throughout storage, when compared to the Control ones. A range of treatment induced sensory characteristics, partly associated to Maillard reactions, were developed in the Treated fillets. Overall, the treatment affected positively both the raw and cooked quality of the fillet, showing promising results as a shelf-life extension method for fish fillet preservation.