Application of gelatin-based zinc oxide nanoparticles bionanocomposite coatings to control Listeria monocytogenes in Talaga cheese and camel meat during refrigerated storage.

Listeria monocytogenes is a concerning foodborne pathogen incriminated in soft cheese and meat-related outbreaks, highlighting the significance of applying alternative techniques to control its growth in food. In the current study, eco-friendly zinc oxide nanoparticles (ZnO-NPs) were synthesized using Rosmarinus officinalis, Punica granatum, and Origanum marjoram extracts individually. The antimicrobial efficacy of the prepared ZnO-NPs against L. monocytogenes was assessed using the agar well diffusion technique. Data indicated that ZnO-NPs prepared using Origanum marjoram were the most effective; therefore, they were used for the preparation of gelatin-based bionanocomposite coatings. Furthermore, the antimicrobial efficacy of the prepared gelatin-based bionanocomposite coatings containing eco-friendly ZnO-NPs was evaluated against L. monocytogenes in Talaga cheese (an Egyptian soft cheese) and camel meat during refrigerated storage at 4 ± 1 oC. Talaga cheese and camel meat were inoculated with L. monocytogenes, then coated with gelatin (G), gelatin with ZnO-NPs 1% (G/ZnO-NPs 1%), and gelatin with ZnO-NPs 2% (G/ZnO-NPs 2%). Microbiological examination showed that the G/ZnO-NPs 2% coating reduced L. monocytogenes count in the coated Talaga cheese and camel meat by 2.76 ± 0.19 and 2.36 ± 0.51 log CFU/g, respectively, by the end of the storage period. Moreover, G/ZnO-NPs coatings controlled pH changes, reduced water losses, and improved the sensory characteristics of Talaga cheese and camel meat, thereby extending their shelf life. The obtained results from this study indicate that the application of gelatin/ZnO-NPs 2% bionanocomposite coating could be used in the food industry to control L. monocytogenes growth, improve quality, and extend the shelf life of Talaga cheese and camel meat.

Effect of thyme, ginger, and their nano-particles on growth performance, carcass characteristics, meat quality and intestinal bacteriology of broiler chickens.

This study was conducted to evaluate the effects of thyme, ginger, and their nano-particles, as alternatives to antibiotic growth promotors (AGP), on productive performance, carcass traits, meat quality and gut health of broiler chickens. A total of 270 one-day-old broiler chicks were randomly distributed into 6 groups, each consisting of 3 replicates (n = 15 chicks/replicate). The birds in group 1 were fed the control diet which contained neither antibiotic growth promotors nor phytogenic feed additives (PFA). Birds in group 2 were fed diets containing 0.05% of AGP (Bacitracin methylene disalicylate). Chicks in group 3 and 4 were fed diets supplemented with 1.0% of thyme and ginger, respectively, whereas birds in group 5 and 6 were offered diets including 0.10% of nano-thyme and nano-ginger, respectively. The experiment lasted for 35 days. It was found that thyme and ginger with their nano-products, like the antibiotic, improved the body weight, weight gain and feed conversion rate of birds. The effect of ginger and nano-ginger on body weight and weight gain was greater than other treatments. During the overall feeding period, the feed cost of production was the highest in antibiotic group, but was the lowest in ginger and nano-ginger treatments. There was no effect of dietary treatments on carcass yield or organs weight except bursa of Fabricius and abdominal fat. Thyme, ginger and their nano-composites increased the weight of bursa and reduced the abdominal fat amount. The phytogenic additives and their nano-particles improved the colour, water holding capacity, and flavor of meat. Moreover, these additives reduced the total intestinal bacterial count as well as the total aerobic mesophilic count of meat. The effect of PFA and their nano-particles on the bacterial count was similar to that of antibiotic. In conclusion, thyme and ginger with their nano- particles can be considered as promising agents in feeding of broilers to improve the growth performance, gut health and meat quality. Moreover, these additives can be used as alternatives to AGP to overcome its health hazards and the high cost. The nanotechnology of herbal plants enables them to be added in smaller amounts in poultry diets with producing the same effect of raw ingredients, and this could be due to the higher bioavailability.

Rapid and sensitive in situ detection of heavy metals in fish using enhanced Raman spectroscopy.

Heavy metals have been widely applied in industry, agriculture, and other fields because of their outstanding physics and chemistry properties. They are non-degradable even at low concentrations, causing irreversible harm to the human and other organisms. Therefore, it is of great significance to develop high accuracy and sensitivity as well as stable techniques for their detection. Raman scattering spectroscopy and atomic absorption spectrophotometer (AAS) were used parallelly to detect heavy metal ions such as Hg, Cd, and Pb of different concentrations in fish samples. The concentration of the heavy metals is varied from 5 ppb to 5 ppm. Despite the satisfactory recoveries of AAS, their drawbacks are imperative for an alternative technique. In Raman scattering spectroscopy, the intensities and areas of the characteristic peaks are increased with increasing the concentration of the heavy metals. For Hg concentration ≥ 1 ppm, a slight shift is observed in the peak position. The obtained values of peak intensity and peak area are modeled according to Elvoich, Pseudo-first order, Pseudo-second order, and asymptotic1 exponential model. The best modeling was obtained using the Elovich model followed by the asymptotic1 exponential model. The introduced Raman spectroscopy-based approach for on-site detection of trace heavy metal pollution in fish samples is rapid, low-cost, and simple to implement, increasing its visibility in food safety and industrial applications.

Effect of chitosan-gelatin coating fortified with papaya leaves and thyme extract on quality and shelf life of chicken breast fillet and Kareish cheese during chilled storage.

A novel antimicrobial chitosan-gelatin based edible coating fortified with papaya leaves and thyme extract was prepared for improving the quality and shelf-life of chicken breast fillet and Kareish cheese during chilled storage at 4 ± 1 °C. The samples were dipped for 10 min in distilled water (control), chitosan-gelatin (CG), chitosan-gelatin +2% papaya leaves extract (CG + P) and chitosan-gelatin +2% thyme extract (CG + Th). The coated and uncoated samples were examined periodically for sensory attributes, pH, TBARs, total aerobic mesophilic (TAM), total Enterobacteriaceae (TE), and total yeasts and molds counts (TYM). Sensory evaluation revealed that chicken breast fillet and Kareish cheese samples coated with CG + P were the best in terms of tenderness, juiciness, body & texture and flavor. CG + Th exhibited the highest antimicrobial and antioxidant effect, followed by CG + P. The results of microbiological, physicochemical and sensory analysis of this study demonstrated that the application of CG + P or CG + Th could be a promising method for increasing the shelf life and improving the quality of chicken breast fillet and Kareish cheese.

Biomimetic magnetic sensor for electrochemical determination of scombrotoxin in fish.

This work addresses a novel, rapid and cost-effective approach for the electrochemical sensing of scombrotoxin (histamine) in fish based on magnetic molecularly imprinted polymer (magnetic-MIP). The histamine magnetic-MIP was synthesized by the core-shell method using histamine as a template, and 2-vinyl pyridine as functional monomer. The magnetic-MIP was characterized by TEM, SEM, and confocal microscopy. Additionally, the binding capacity of magnetic-MIP towards histamine was investigated and compared with magnetic non-molecularly imprinted polymer (magnetic-NIP). This biomimetic material merged the advantages of MIPs and magnetic particles (MPs), including low cost of production, stability, high binding capacity and can be easily separated by the aid of a permanent magnet. The magnetic-MIP was integrated into magneto-actuated electrodes for the direct electrochemical detection of histamine preconcentrated from fish samples. The results revealed that this approach succeeded in the preconcentration and determination of histamine with a LOD as low as 1.6 × 10-6 mg L-1, much lower than the index for fish spoilage (50 mg kg-1) accordingly to the legislation. Furthermore, the analytical performance was validated for the determination of histamine in scombroid fish samples with recovery values ranging from 96.8 to 102.0 %, confirm so it can be applied easily for routine food examination.

Electrochemical sensing of methyl parathion on magnetic molecularly imprinted polymer.

The electrochemical detection of methyl parathion in fish was performed by preconcentrating the pesticide on magnetic molecularly imprinted polymer and further readout on magneto-actuated electrode by square wave voltammetry. The magnetic molecularly imprinted polymer was synthesized by a magnetic core-shell strategy, using methacrylic acid as a functional monomer, and selected by theoretical calculation using the density functional theory (DFT). The characterization of this material was performed by SEM, TEM and XRD. Moreover, the binding capacity and selectivity towards methyl parathion was studied and compared with the corresponding magnetic non-imprinted polymer. The magneto-actuated electrochemical sensor showed outstanding analytical performance for the detection of methyl parathion in fish, with a limit of detection of as low as 1.22 × 10-6 mg L-1 and recovery values ranging from 89.4% to 94.7%. The magnetic molecularly imprinted polymer successfully preconcentrated the analyte from the complex samples and paves the way to incorporate this material in other platforms for the detection of this pesticide in the field of environmental control and food safety.

Awareness and practice of patients' rights among hospitalized patients at Wad-Medani Teaching Hospital, Sudan.

Patients' rights are a fundamental human right and an important part of modern health care practice. This is a cross-sectional descriptive analytic study, conducted amongst 263 patients at Wadi-Medani Teaching Hospital, Sudan, in March-April 2015. Most patients (95.2%) did not know about the Bill of Rights and most of them (92.8%) were not able to mention any of the patients' rights. The most practiced rights were: the right to be asked for permission before examination (88.1%), proper handling (87.8%), safety of the hospital (87%), presence of a third person when examining a female by a male doctor (85.6%), and admission file confidentiality (75.5%). The awareness of Sudan FMOH Patients' Bill of Rights was very low among patients at Wad-Medani Teaching Hospital, yet they showed a high satisfaction rate probably due to their low socioeconomic status, educational level and expectations. Therefore, awareness of patients' rights must be increased.