National Energy Commission

Abstract This work investigates the adsorption of Mn 2+ ions on hydrothermally synthesized Nb 2 O 5 nanoparticles obtained via an oxidant peroxo method, with particular emphasis on the role of functional groups present on the nanoparticle surface. Orthorhombic Nb 2 O 5 was formed at a mild temperature (100 °C), yielding nanocrystalline particles with high colloidal stability and a strongly negative surface charge. FTIR and zeta potential analyses reveal a carbonyl and hydroxyl-rich surface that promotes electrostatic attraction toward Mn 2+ species. Adsorption experiments demonstrate rapid Mn 2+ uptake, reaching equilibrium within minutes, with kinetics best described by a pseudo-first-order model, indicating a physisorption-dominated process. Equilibrium data are best fitted by the Freundlich and Redlich–Peterson isotherms, reflecting surface heterogeneity and multilayer adsorption, with an experimental adsorption capacity approaching 116.67 mg g −1 . These findings demonstrate that hydrolyzed Nb 2 O 5 is an efficient and tunable adsorbent for Mn 2+ removal, offering strong potential for water treatment and environmental remediation applications. Graphical abstract

Frozen samples of mechanically deboned chicken meat (MDCM) with skin were irradiated with gamma radiation doses of 0.0 kGy (control) and 3 kGy at 2 different radiation dose rates: 0.32 kGy/h (3 kGy) and 4.04 kGy/h (3 kGy). Batches of irradiated and control samples were evaluated during 11 d of refrigerated (2 ± 1 °C) storage for the following parameters: total psychrotrophic bacteria count, thiobarbituric acid reactive substances (TBARS), evaluation of objective color (L*, a*, and b*) and a sensory evaluation (irradiated odor, oxidized odor, pink and brown colors). No statistical difference (P > 0.05) was found amongst the TBARS values obtained for the MDCM samples irradiated with dose rates of 0.32 and 4.04 kGy/h. There was a significant increase (P < 0.05) in the psychrotrophic bacterial count as from the 7th day of refrigerated storage, for the MDCM samples irradiated at the dose rate of 4.04 kGy/h. With respect to the attribute of oxidized odor, the samples irradiated with a dose rate of 0.32 kGy/h showed a stronger intensity and were significantly different (P < 0.05) from the sample irradiated with a dose rate of 4.04 kGy/h on days 0 and 2 of refrigerated storage. Irradiation with a dose rate of 4.04 kGy/h (3 kGy) was shown to be the best condition for the processing of MDCM according to the evaluation of all the variables, under the conditions of this study. Practical Application: The results obtained for the application of different dose rates of ionizing radiation to mechanically deboned chicken meat will provide the food industry with information concerning the definition of the best processing conditions to maximize the sensory and food quality.

Ionizing radiation was used for the purpose of reducing bacterial contamination in mechanically deboned chicken meat (MDCM). Irradiated and non-irradiated MDCM stored at -18±1 °C, and samples were taken at zero time and at 30-day intervals up to 90 days for 2-thiobarbituric acid reactive substances, sensory and microbiological analyses. The results obtained for the microbiological, sensory and lipid oxidation evaluations, showed that the MDCM samples irradiated with doses of 3.0 and 4.0 kGy were all considered acceptable during 90 days of frozen storage.