175 research outputs found

    Sodium butyrate in growing and fattening diets for early-weaned rabbits

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    [EN] To study the effect of adding coated sodium butyrate (SB) to growing-fattening rabbit diets, 2 trials were conducted. In trial 1, 180 rabbits were housed in pairs and fattened from 23 (weaning) to 63 d of age to evaluate their zootechnical performance. Trial 2 involved 30 rabbits, from 23 to 37 d of age and housed individually in digestibility cages, to evaluate digestibility, caecal fermentative activity and morphology of the intestinal mucosa. In both trials rabbits were randomly divided into 2 groups, each receiving one of the following diets: control diet [CTR, 360 g neutral detergent fibre (NDF) and 170 g crude protein (CP)/kg dry matter (DM)] and SB diet. The SB diet, similar to CTR diet, included coated SB at 5 g/kg by replacement of an identical quantity of wheat. In trial 1, after the first 2 wk, the SB content was reduced from 5 to 3 g/kg. In trial 2, faeces were collected over the last 6 d (32-37 d of age), with rabbits being slaughtered at 37 d of age. Gastric and caecal pH were measured and fermentative activity was determined in caecal contents. Three sections of the small intestine were excised from 20 rabbits (10 per treatment) for microscopic examination of intestinal villi and crypts in the proximal region, central region and distal region. In the first 2 wk after weaning, SB rabbits grew 8% less than their counterparts (P=0.002), but had a better feed conversion ratio (1.58 vs. 1.61; P=0.036). During the whole trial 1 period, SB improved feed conversion (P=0.005) and decreased feed intake (104.1 CTR vs. 98.8 g/d SB; P=0.017). No difference was recorded in daily weight gain (42.7 vs. 42.9 g/d). In both diets, the digestibility of DM, organic matter, energy, CP and NDF were similar. In the 3 intestinal regions of rabbits fed SB diet, crypts were deeper (P<0.05). There were no significant differences in villus height and width between treatments. Pectinase activity was higher (P=0.054) with SB diet, but cellulase and xylanase activity remained unaffected by diet. In our experimental conditions, the addition of SB allowed an improvement in feed conversion.Ribeiro, J.; Gaspar, S.; Pinho, M.; Freire, JPB.; Falcão-E-Cunha, L. (2012). Sodium butyrate in growing and fattening diets for early-weaned rabbits. World Rabbit Science. 20(4):199-207. doi:10.4995/wrs.2012.1233SWORD19920720

    Mixtures of polymers and cholinium-based ionic liquids to tailor the phase diagrams and extraction efficiency of aqueous biphasic systems

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    Aqueous biphasic systems (ABS) are outstanding alternatives over conventional liquid-liquid extraction processes since it is avoided the use of volatile and hazardous organic solvents (VOCs). ABS are more biocompatible systems formed by two aqueous-rich phases that can be designed by combining different pairs of solutes (polymer-polymer, polymer-salt or salt-salt) above specific concentrations. In the past years, ABS have been studied as powerful techniques for purification, separation and extraction purposes. Ionic liquids (ILs) have been described as interesting fluids towards the development of more sustainable processes. Due to the ILs unique properties, their introduction in ABS led to systems with higher selectivity and extraction performance for a wide plethora of compounds. In fact, it was already shown that ILs allow to overcome the low hydrophilic-hydrophobic range of ABS composed of two polymers or one polymer and one inorganic salt. IL-based ABS formed with polyethylene glycol (PEG) polymers were recently introduced and a successful control of the phase polarities, through the manipulation of the IL chemical structure, was demonstrated. Lately, it was also demonstrated that a new class of natural-derived cholinium-based ILs are capable of undergoing two phase separation by the addition of PEGs with different molecular weights. In the present work, mixtures of PEGs with different molecular weights (400 and 2000 g/mol) were used to ascertain on the formation ability of ABS composed of water and cholinium-based ILs or salts. The results obtained indicate that the formation ability of these ABS increase with the content of PEG2000 over PEG400 (and follow a continuous increase), meaning that a close-fitting control on their phases polarity can be attained. These systems were then evaluated on their performance for extracting a series of alkaloids with different polarities, namely caffeine, theophylline, theobromine and nicotine. In general, the alkaloids partition extent to the most hydrophobic phase (PEG-rich) follows their polarity/hydrophobicity. In summary, it is here demonstrated that mixtures of polymers as phase-forming components of ABS allow to tailor the partition coefficients of different alkaloids and their use in the purification of added-value compounds from biomass extracts is straightforwardly foreseen.publishe

    Opposite effects induced by cholinium-based ionic liquid electrolytes in the formation of aqueous biphasic systems comprising polyethylene glycol and sodium polyacrylate

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    Cholinium-based ionic liquids ([Ch]-based ILs) were investigated as electrolytes in the formation of aqueous biphasic systems (ABS) composed of polyethylene glycol (PEG) and sodium polyacrylate (NaPA) polymers. Both enhancement and decrease in the liquid-liquid demixing ability induced by electrolytes in PEG-NaPA aqueous biphasic systems were observed. It is shown that the ILs that most extensively partition to the PEG-rich phase tend to act as inorganic salts enhancing the two-phase formation ability, while those that display a more significant partition to the NaPA-rich phase decrease the ABS formation capacity. The gathered results allowed us to confirm the tailoring ability of ILs and to identify, for the first time, opposite effects induced by electrolytes on the PEG-NaPA ABS formation ability. The distribution of the electrolyte ions between the coexisting phases and the polyelectrolyte ion compartmentalization are key factors behind the formation of PEG-NaPA-based ABS.publishe

    Aqueous biphasic systems composed of ionic liquids: one-step extraction/concentration techniques for water pollution tracers

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    Emergent micropollutants have become a serious global problem with a large impact in the environment and human health, while their presence in aquatic systems has been registered as ranging from ng/L-1 to ug/L-1. Pharmaceuticals are ubiquitous micropollutants since their continuous consumption and consequent release via human excretions into aqueous systems are inevitable. Due to their usually low concentrations in aqueous samples, the development of a pre-concentration technique in order to continuously quantify and to monitor these components in aqueous streams is of major relevance. Aqueous biphasic systems (ABS) composed of ionic liquids (ILs) can be seen as more sustainable separation processes since they avoid the use of volatile and hazardous organic solvents (VOCs). As liquid-liquid systems, ABS can be used as extraction, purification and concentration platforms. Due to the outstanding tunable properties of ILs, IL-based ABS provide higher and more selective extraction efficiencies for a wide range of compounds when compared to traditional polymer-based ABS. IL-based ABS were already employed and adequately characterized for the extraction and concentration of endocrine disruptors, either from biological fluids or aqueous matrices. The aim of this work is to demonstrate the applicability of IL-based ABS to completely extract and concentrate, in one-step, two different and representative pharmaceutical pollution tracers, namely caffeine (CAF) and carbamazepine (CBZ). The low concentration of these persistent pollutants (usually found in ug/L-1 and ng/L-1 levels) does not allow a proper detection and quantification by conventional analytical equipment without a previous concentration step. However, pre-concentration methods commonly applied are costly, time-consuming, provide irregular recoveries and/or use VOCs. In this work, ABS composed of the IL tetrabutylammonium chloride ([N4444]Cl) and the salt K3C6H5O7 was investigated, demonstrating to be able to completely extract and concentrate CAF and CBZ in a single-step. Moreover, with this pre-treatment step it was demonstrated to be possible to overcome the detection limits of a high performance liquid chromatography coupled to an UV-Vis detector equipment. The results obtained demonstrate that IL-based ABS are versatile pre-concentration techniques, and can be used for the extraction and concentration of a large plethora of other micropollutants from environmental aqueous matrices.publishe

    Economic evaluation of the primary recovery of tetracycline with traditional and novel aqueous two-phase systems

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    Antibiotics are a key pharmaceutical to inhibit growth or kill microorganisms. They represent a profitable market and, in particular, tetracycline has been listed as an essential medicine by the WHO. Therefore it is important to improve their production processes. Recently novel and traditional aqueous two-phase systems for the extraction have been developed with positive results. The present work performs an economic analysis of the production and recovery of tetracycline through the use of several ATPS through bioprocess modeling using specialized software (BioSolve, Biopharm Services Ltd, UK) to determine production costs per gram (CoG/g). First, a virtual model was constructed using published data on the recovery of tetracycline and extended to incorporate uncertainties. To determine how the model behaved, a sensitivity analysis and Monte Carlo simulations were performed. Results showed that ATPS formed by cholinium chloride/K3PO4 was the best option to recover tetracycline, as it had the lowest CoG/g (US$ 672.83/g), offered the highest recovery yield (92.42%), second best sample input capacity (45% of the ATPS composition) and one of the lowest materials contribution to cost. The ionic liquid-based method of ATPS is a promising alternative for recovering tetracycline from fermentation broth.publishe

    Glutamine and cystine-enriched diets modulate aquaporins gene expression in the small intestine of piglets

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    Research Areas: Science & Technology ; Other TopicsABSTRACT - The regulation of glycerol permeability in the gastrointestinal tract is crucial to control fat deposition, lipolysis and gluconeogenesis. Knowing that the amino acid glutamine is a physiological regulator of gluconeogenesis, whereas cystine promotes adiposity, herein we investigated the effects of dietary supplementation with glutamine and cystine on the serum biochemical parameters of piglets fed on amino acid-enriched diets, as well as on the transcriptional profile of membrane water and glycerol channels aquaporins (AQPs) in the ileum portion of the small intestine and its impact on intestinal permeability. Twenty male piglets with an initial body weight of 8.8 ± 0.89 kg were allocated to four dietary treatments (n = 5) and received, during a four week-period, a basal diet without supplementation (control) or supplemented with 8 kg/ton of glutamine (Gln), cystine (Cys) or the combination of the two amino acids in equal proportions (Gln + Cys). Most biochemical parameters were found improved in piglets fed Gln and Cys diet. mRNA levels of AQP3 were found predominant over the others. Both amino acids, individually or combined, were responsible for a consistent downregulation of AQP1, AQP7 and AQP10, without impacting on water permeability. Conversely, Cys enriched diet upregulated AQP3 enhancing basolateral membranes glycerol permeability and downregulating glycerol kinase (GK) of intestinal cells. Altogether, our data reveal that amino acids dietary supplementation can modulate intestinal AQPs expression and unveil AQP3 as a promising target for adipogenesis regulation.info:eu-repo/semantics/publishedVersio

    Alkaloids as alternative probes to characterize the relative hydrophobicity of aqueous biphasic systems

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    In order to overcome the lack of characterization on the relative hydrophobicity of aqueous biphasic systems (ABS), the partition of three alkaloids as alternative probes, was evaluated in a series of biocompatible ABS composed of cholinium-based salts or ionic liquids (ILs) and polyethylene glycol (PEG). The caffeine partitioning in ABS was firstly addressed to infer on the effect of the phase-forming components composition. In all systems, caffeine preferentially concentrates in the lower water content PEG-rich phase. Additionally, a linear dependence between the logarithmic function of the partition coefficients and the water content ratio was found. To confirm this linear dependency, the partition coefficients of caffeine, theobromine and theophylline were determined in other ABS formed by different cholinium-based salts/ILs. In most systems, it is shown that all alkaloids partition to the most hydrophobic phase. To support the experimental results, COSMO-RS (Conductor-like Screening Model for Real Solvents) was used to compute the screening charge distributions of both phaseforming components of ABS and alkaloids, the excess enthalpy of mixing and the activity coefficients at infinite dilution. It is here demonstrated that the partition trend of alkaloids can be used to address the relative hydrophobicity of the coexisting phases in polymer-salt/-IL ABS

    Simultaneous Separation of Antioxidants and Carbohydrates From Food Wastes Using Aqueous Biphasic Systems Formed by Cholinium-Derived Ionic Liquids

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    project CICECO-Aveiro Institute of Materials, UID/CTM/50011/2019. Associate Laboratory for Green Chemistry-LAQV, FCT Ref. UID/QUI/50006/2019. POCI-01-0145-FEDER-016403. Investigator FCT project IF/00621/2015. Programa Mais Centro under project CENTRO-07-ST24-FEDER-002008. COMPETE: PEst-C/SAU/UI0709/2011.The food industry produces significant amounts of waste, many of them rich in valuable compounds that could be recovered and reused in the framework of circular economy. The development of sustainable and cost-effective technologies to recover these value added compounds will contribute to a significant decrease of the environmental footprint and economic burden of this industry sector. Accordingly, in this work, aqueous biphasic systems (ABS) composed of cholinium-derived bistriflimide ionic liquids (ILs) and carbohydrates were investigated as an alternative process to simultaneously separate and recover antioxidants and carbohydrates from food waste. Aiming at improving the biocompatible character of the studied ILs and proposed process, cholinium-derived bistriflimide ILs were chosen, which were properly designed by playing with the cation alkyl side chain and the number of functional groups attached to the cation to be able to create ABS with carbohydrates. These ILs were characterized by cytotoxicity assays toward human intestinal epithelial cells (Caco-2 cell line), demonstrating to have a significantly lower toxicity than other well-known and commonly used fluorinated ILs. The capability of these ILs to form ABS with a series of carbohydrates, namely monosaccharides, disaccharides and polyols, was then appraised by the determination of the respective ternary liquid-liquid phase diagrams at 25 degrees C. The studied ABS were finally used to separate carbohydrates and antioxidants from real food waste samples, using an expired vanilla pudding as an example. With the studied systems, the separation of the two products occurs in one-step, where carbohydrates are enriched in the carbohydrate-rich phase and antioxidants are mainly present in the IL-rich phase. Extraction efficiencies of carbohydrates ranging between 89 and 92% to the carbohydrate-rich phase, and antioxidant relative activities ranging between 65 and 75% in the IL-rich phase were obtained. Furthermore, antioxidants from the IL-rich phase were recovered by solid-phase extraction, and the IL was recycled for two more times with no losses on the ABS separation performance. Overall, the obtained results show that the investigated ABS are promising platforms to simultaneously separate carbohydrates and antioxidants from real food waste samples, and could be used in further related applications foreseeing industrial food waste valorization.publishersversionpublishe
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