707 research outputs found
Adsorption of phenol/tyrosol from aqueous solutions on macro-reticular aromatic and macro-porous polystyrene cross-linked with divinylbenzene polymeric resins
The current work aims at separating by adsorption of low-molecular-weight organic compounds in a
nanofiltration concentrate of the olive mill wastewaters. The experimental investigations on adsorption of
phenol/tyrosol in single and binary systems were conducted in batch mode by using the commercially
available macroporous resins FPX66 and MN202. The structures of such resins were examined by FTIR
before and after adsorption. The operating parameters affecting the adsorption process such as resin dosage,
contact time, pH, and initial concentration of phenol/tyrosol were investigated. Fast phenol and tyrosol uptakes
were observed for both resins. It can be attributed to their physical properties, for instance high specific area
and microporous area. The adsorption selectivity of phenol is larger than tyrosol when using FPX66 resin, but
smaller if MN202 resin is used. Acidic pH appeared to be always favourable for the adsorption. A synergetic
effect between solutes was observed since adsorption of phenol and tyrosol in the binary systems was faster
than the individual sorption of each solute. Five isotherms namely Langmuir, Freundlich, DubininRadushkevich,
Temkin and Redlich-Peterson were selected to fit the obtained equilibrium experimental data.
Finally, desorption of the examined compounds with ethanol (EtOH) allowed a maximum around 85 % of
phenol, and equal to 94 % of tyrosol on FPX66 and MN202 resins
Adsorption of phenol/tyrosol from aqueous solutions on macro-reticular aromatic and macro-porous polystyrene cross-linked with divinylbenzene polymeric resins
The current work aims at separating by adsorption of low-molecular-weight organic compounds in a
nanofiltration concentrate of the olive mill wastewaters. The experimental investigations on adsorption of
phenol/tyrosol in single and binary systems were conducted in batch mode by using the commercially
available macroporous resins FPX66 and MN202. The structures of such resins were examined by FTIR
before and after adsorption. The operating parameters affecting the adsorption process such as resin dosage,
contact time, pH, and initial concentration of phenol/tyrosol were investigated. Fast phenol and tyrosol uptakes
were observed for both resins. It can be attributed to their physical properties, for instance high specific area
and microporous area. The adsorption selectivity of phenol is larger than tyrosol when using FPX66 resin, but
smaller if MN202 resin is used. Acidic pH appeared to be always favourable for the adsorption. A synergetic
effect between solutes was observed since adsorption of phenol and tyrosol in the binary systems was faster
than the individual sorption of each solute. Five isotherms namely Langmuir, Freundlich, DubininRadushkevich,
Temkin and Redlich-Peterson were selected to fit the obtained equilibrium experimental data.
Finally, desorption of the examined compounds with ethanol (EtOH) allowed a maximum around 85 % of
phenol, and equal to 94 % of tyrosol on FPX66 and MN202 resins
Toxicological Impact of Rare Earth Elements (REEs) on the Reproduction and Development of Aquatic Organisms Using Sea Urchins as Biological Models
The growing presence of lanthanides in the environment has drawn the attention of the scientific community on their safety and toxicity. The sources of lanthanides in the environment include diagnostic medicine, electronic devices, permanent magnets, etc. Their exponential use and the poor management of waste disposal raise serious concerns about the quality and safety of the ecosystems at a global level. This review focused on the impact of lanthanides in marine organisms on reproductive fitness, fertilization and embryonic development, using the sea urchin as a biological model system. Scientific evidence shows that exposure to lanthanides triggers a wide variety of toxic insults, including reproductive performance, fertilization, redox metabolism, embryogenesis, and regulation of embryonic gene expression. This was thoroughly demonstrated for gadolinium, the most widely used lanthanide in diagnostic medicine, whose uptake in sea urchin embryos occurs in a time-and concentration-dependent manner, correlates with decreased calcium absorption and primarily affects skeletal growth, with incorrect regulation of the skeletal gene regulatory network. The results collected on sea urchin embryos demonstrate a variable sensitivity of the early life stages of different species, highlighting the importance of testing the effects of pollution in different species. The accumulation of lanthanides and their emerging negative effects make risk assessment and consequent legislative intervention on their disposal mandatory
Effect of beetroot (Beta vul-garis) extract on black angus burgers shelf life
Beef burgers are meat preparations with easy perishability. To ensure a longer shelf-life, the Regulation EU 1129/11 allows the use of some additives. However, health-conscious consumers prefer products which do not contain synthetic substances. Aim of the present study was to evaluate the effect of Red Beetroot (Beta vulgaris) integration on Black Angus made burgers shelf life. Red beet was prepared as powder and added to meat mixture as the same or in water solution. The study was split into 2 trials to assess the extract activity also in burgers vacuum-packaged stored. Burgers were analysed (up to 9 days at 4°C) in terms of sensory properties, microbiological profile, pH, aw and lipid oxidation (TBARS). At the end of storage, treated samples showed the highest values of redness and the lowest content of malondialdehyde, probably due to antioxidant properties of red beet towards myoglobin and lipid oxidation processes. Moreover, results highlighted that Red Beetroot activities were dose-dependent and intensified if dissolved in water. The aw values did not appear to be conditioned by extract integrations, unlike the pH that was lower in treated samples than control ones. Microbiological analyses identified beet-root as a potential antimicrobial substance, especially in high concentration. In conclusion, Beta vulgaris extract could be pro-posed as natural compound exploitable in beef burgers to preserve qualities and extend their shelf-life
lipid oxidation in buffalo meat from animals with dietary supplementation of vitamin e
Buffalo (Bubalus bubalis) meat is not widely used in the diet, but it is recently reconsidered due to its valuable nutritional qualities. New strategies aiming to improve the quality of buffalo meat have to be applied particularly to face the problem of lipid peroxidation, one of the most important causes of meat food deterioration. The aim of this study was to evaluate the lipid oxidation of buffalo meat (muscles Caput longum tricipitis brachii, Longissimus dorsi and Semimembranosus), coming from animals fed with two different amount of vitamin E (600 IU/die and 1500 IU/die for 102 -123 days) considering, as markers for lipid oxidation, the concentration of malondialdehyde (MDA) by HPLC-UV and TBA test. Moreover it was evaluated, by HPLC-DAD, vitamin E concentration in the meat samples. Muscles coming from animals with vitamin E supplementation were in mean 2 times more enriched of vitamin E than control (p < 0.05). Meat from buffalo fed with 600 IU/die vitamin E had significant lower MDA concentration in comparison with control (in mean -53%, n= 4). Both for MDA and vitamin E concentrations not significant differences were found between the supplementation of 600 IU/die and 1500 IU/die. It is concluded that dietary supplementation with Vitamin E is a promising strategy to prevent lipid oxidation of buffalo meat and to prolong its shelf-life
Type-1 cannabinoid receptor expression in the frog, Rana esculenta, tissues: a possibile involvement in the regulation of testicular activity
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