1,432 research outputs found

    PUFA loses after cookingg of chicken meat

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    An experiment was conducted to assess the effect ofsupplying with fish or linseed oils on the performance, quality parameters and fatty acid (FA) composition of the meat of broiler chickens. Besides, it aimed to test the relative stability of the FA composition after cooking of the chicken meat. A diet with 4% of tallow plus 4% linseed oil (Tl ) or 4% fish oil (T2) was fed to the birds throughout the 5 wk growth period. After slaughtering of the animals, the FA profile of the raw samples was determined by means of gas chromatography, and also alter cooking in a convector oven (180"C, 35 min). Carcass yield, percentage of valuable parts, texture, juiciness and grill losses of meat were determined as objective quality parameters. Performance parameters were not significantly different among treatments, though a tendency towards a better transformation index was found in Tl fed animals (p<().09). Objective quality meat parameters were not different when compared by treatments. As expected, differences in the FA profile of the samples were found among treatments, being the Tl samples the ones which scored with higher n-3 FA levels, because of its linolenic acid content, while T2 samples showed a higher proportion in n-3 long-chain (LC) polyunsaturated FA (PUFA) in form ofeicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid. Processing of the samples had an important influence on the FA profile of the meat. PUFA content was significantly lower in cooked samples (p<0.()l), thus affecting the relative percentage of saturated FA, which rose to the highest values after cooking. Changes in monounsaturated FA were unnoticeable. Losses in n-6 FA were mainly due to the fall of linoleic acid while almost all n-3 LCPUFA experienced significant losses after cooking of the meat

    Ins1 (Cre) knock-in mice for beta cell-specific gene recombination.

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    AIMS/HYPOTHESIS: Pancreatic beta cells play a central role in the control of glucose homeostasis by secreting insulin to stimulate glucose uptake by peripheral tissues. Understanding the molecular mechanisms that control beta cell function and plasticity has critical implications for the pathophysiology and therapy of major forms of diabetes. Selective gene inactivation in pancreatic beta cells, using the Cre-lox system, is a powerful approach to assess the role of particular genes in beta cells and their impact on whole body glucose homeostasis. Several Cre recombinase (Cre) deleter mice have been established to allow inactivation of genes in beta cells, but many show non-specific recombination in other cell types, often in the brain. METHODS: We describe the generation of Ins1 (Cre) and Ins1 (CreERT2) mice in which the Cre or Cre-oestrogen receptor fusion protein (CreERT2) recombinases have been introduced at the initiation codon of the Ins1 gene. RESULTS: We show that Ins1 (Cre) mice induce efficient and selective recombination of floxed genes in beta cells from the time of birth, with no recombination in the central nervous system. These mice have normal body weight and glucose homeostasis. Furthermore, we show that tamoxifen treatment of adult Ins1 (CreERT2) mice crossed with Rosa26-tdTomato mice induces efficient recombination in beta cells. CONCLUSIONS/INTERPRETATION: These two strains of deleter mice are useful new resources to investigate the molecular physiology of pancreatic beta cells

    PUFA Losses after Cooking of Chicken Meat

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    To study the changes of the fatty acid (FA) profile of Long-Chain omega-3 (LCn3) enriched meat after coo¬ king under consumer conditions

    The role of the operating parameters of SBR systems on the SMP production and on membrane fouling reduction

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    [EN] In this work, six identical laboratory SBRs treating simulated wastewater were operated in parallel studying the effect of three food-to-microorganisms ratio (F/M ratio; 0.20, 0.35 and 0.50 kg COD¿kg MLSS-1¿d-1), two hydraulic retention times (HRT; 24 and 16 h) and two values of number of cycles per day (3 and 6). Influence of these operational parameters on the SMPs production and reactor performance, were studied. Results indicated that the highest F/M ratio, HRT and cycles/day produced 72.7% more of SMP. In a second experimental series, biological process yielding the maximal and the minimal SMPs production were replicated and both mixed liquors (ML) and treated effluents were ultrafiltrated. The flux decay in the conditions of minimum and maximum SMPs production were 52% and 72%, when the SBRs effluents were ultrafiltrated while no significant differences in the ultrafiltration of ML were found. In terms of permeability recovery, this was lower for the case of the ML (73% and 49% of initial permeability recovered for effluent and ML ultrafiltration, respectively).This work was supported by the Spanish Ministerio de Economia y Competitividad (CTM2014-54546-P).Ferrer-Polonio, E.; White, K.; Mendoza Roca, JA.; Bes-Piá, M. (2018). The role of the operating parameters of SBR systems on the SMP production and on membrane fouling reduction. Journal of Environmental Management. 228:205-212. https://doi.org/10.1016/j.jenvman.2018.09.036S20521222

    A model based on Hirano-Exner equations for two-dimensional transient flows over heterogeneous erodible beds

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    In order to study the morphological evolution of river beds composed of heterogeneous material, the interaction among the different grain sizes must be taken into account. In this paper, these equations are combined with the two-dimensional shallow water equations to describe the flow field. The resulting system of equations can be solved in two ways: (i) in a coupled way, solving flow and sediment equations simultaneously at a given time-step or (ii) in an uncoupled manner by first solving the flow field and using the magnitudes obtained at each time-step to update the channel morphology (bed and surface composition). The coupled strategy is preferable when dealing with strong and quick interactions between the flow field, the bed evolution and the different particle sizes present on the bed surface. A number of numerical difficulties arise from solving the fully coupled system of equations. These problems are reduced by means of a weakly-coupled strategy to numerically estimate the wave celerities containing the information of the bed and the grain sizes present on the bed. Hence, a two-dimensional numerical scheme able to simulate in a self-stable way the unsteady morphological evolution of channels formed by cohesionless grain size mixtures is presented. The coupling technique is simplified without decreasing the number of waves involved in the numerical scheme but by simplifying their definitions. The numerical results are satisfactorily tested with synthetic cases and against experimental data

    Comparative study of preventive protocols in children at high cariogenic risk.

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    The aim of this study was to compare the efficacy of two preventive protocols - fluoride gel (F) alone or combined with chlorhexidine varnishes (CHX) - on sialochemical, clinical and microbiological parameters in a group of children at high cariogenic risk. Two therapeutic-preventive protocols were applied in 73 children at high cariogenic risk (average age 6.2±1.4 years old) and clinical parameters (simplified oral hygiene index: OHIS; decayed, missing and filled teeth: dmf index; sugar intake and exposure to fluoride), as well as sialochemical parameters (salivary pH and flow, buffer capacity) and microbiological parameters (CFU/mg of dental biofilm of Streptococcus mutans group) were recorded and correlated before and after the protocols. Association was found between parameters that cause deficient control of dental biofilm: high values of OHIS index, CFU/mg dental biofilm, sugar intake and the d component of dmft index, and lower values of salivary flow rate and buffer capacity. After the protocols, a significant decrease was found in OHI-S and CFU/mg dental biofilm. No significant difference was found with children’s gender and age. The association observed between OHI-S and cariogenic bacteria emphasizes the importance of prevention, especially regarding the oral health of the most vulnerable children. The early inclusion of F associated with CHX in the initial step of preventive and therapeutic protocols would provide benefits regarding oral microbe control while children acquire new habits of oral hygiene.publishedVersio

    Development and validation of a computational model for steak double-sided pan cooking

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    The objective of this study was to develop and validate a numerical model to adequately simulate the double-sided pan cooking of beef in a domestic environment. The proposed model takes into account the heat flow from the pan to the meat and the moisture transfer, simultaneously with the meat deformation. The model considers the swelling pressure gradient caused by the shrinkage of the meat fibers and connective tissue due to the denaturation of proteins and the loss of the water holding capacity during cooking. The model results were successfully verified with experimental data of the central temperature and weight loss recorded during cooking for three degrees of doneness. The measured experimental temperatures at the center of the meat were 30 ± 3 °C (very rare), 44 ± 3 °C (rare) and 57 ± 2 °C (done) for a 19 mm steak thickness. Meanwhile, their water losses were 4 ± 2 %, 8 ± 1 % and 11 ± 2 %, respectively. The root mean squared errors of the model predictions were 2.16 °C (very rare), 3.56 °C (rare) and 4.57 °C (done) for the central temperature and 1.48 %, 2.08 % and 2.40 %, respectively for the water loss. The model also correctly predicts cooking times for steaks of different thicknesses, taking weight loss as a reference to set this time. The proposed model is postulated as a useful cooking assistance tool to estimate the optimal cooking time according to consumer preferences

    Effect of 4-nonylphenol on the performance and microbial community of a sequencing batch reactor

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    [EN] 4-nonylphenol (4-NP) is one of the most relevant endocrine-disrupting compounds that can be found in wastewaters. In this work, the effect of dosing 1 mg center dot L 1 of 4-NP to simulated wastewater on the activated sludge process was assessed. For it, two laboratory sequencing batch reactors (SBR) were operated for 94 days, adding 1 mg center dot L 1 of 4-NP to the wastewater entering one of them (SBR-NP), while the other one (SBR-B) worked as a control reactor. Holistic study of 4-NP influence on activated sludge treatment was carried out, which included both the evolution of the biomass characteristics and the effect of this substance on reactor performance. Although the COD removal efficiency in SBR-NP was lower than in the reactor without 4-NP addition (SBR-B), COD removal efficiency of SBR-NP was always higher than 90%. From day 50, nitrification bacteria were inhibited in SBR-NP and cellular viability decreased from 85.7 +/- 11.0% in the first 50 days to 63.0 +/- 10.2% in the last 44 days. Concerning the microbial community analysis, both Nitrosomonas and Nitrospira abundances decreased in SBR-NP (from 0.62% to 0.45%, and from 2.39% to 1.01%, respectively). Proteobacteria abundance was considerably higher in SBR-NP at the end of the experiment (44.28% in SBR-NP and 25.88% in SBR-B), which was due to increase of Aquabacterium genus (13.00% and 0.00% in SBR-NP and SBR-B, respectively), playing an important role in 4-NP degradation. Thus, 4-NP presence, in the concentrations studied, affected heterotrophic and autotrophic bacteria differently, having a negative effect in the second group.Acknowledgements Authors thank the Spanish Ministry of Science, Innovation and Universities for the financial support (Reference of the project: RTI2018-096916-B-I00) .Ferrer-Polonio, E.; Fernández-Navarro, J.; Mendoza Roca, JA.; Bes-Piá, M.; Alonso Molina, JL. (2022). Effect of 4-nonylphenol on the performance and microbial community of a sequencing batch reactor. Journal of Environmental Chemical Engineering. 10(2):1-9. https://doi.org/10.1016/j.jece.2022.1072491910

    Influence of organic matter type in wastewater on soluble microbial products production and on further ultrafiltration

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    [EN] BACKGROUND Membrane fouling is the main limiting factor for the application of ultrafiltration (UF) to wastewater treatment as tertiary treatment or in membrane bioreactors. Soluble microbial products (SMP) play the more important role on membrane fouling. In this work, four sequencing batch reactors were operated in parallel using two different simulated wastewaters under operating conditions maximizing and minimizing SMP production. The aim was to study the influence of the wastewater type, which until now has hardly been considered, on SMP production and, consequently, on membrane fouling. RESULTS AND CONCLUSION Results showed that organic matter (OM) type in wastewater greatly influenced SMP production and composition (protein : carbohydrate ratio). The food¿to¿microorganisms (F : M) ratio also significantly influenced SMP production. The lowest protein : carbohydrate ratio was achieved for wastewater containing sodium acetate as OM source at a F : M = 0.2. Finally, both mixed liquor and treated effluent were subjected to an ultrafiltration (UF) process and it was confirmed that the carbohydrate concentration in SMP was the main parameter influencing membrane fouling when the reactor effluent was fed to the UF process.This work was supported by the Spanish Ministerio de Economia y Competitividad. (CTM2014-54546-P).Ferrer-Polonio, E.; Fernández-Navarro, J.; Alonso Molina, JL.; Bes-Piá, M.; Mendoza Roca, JA. (2018). Influence of organic matter type in wastewater on soluble microbial products production and on further ultrafiltration. Journal of Chemical Technology & Biotechnology. 93(11):3284-3291. https://doi.org/10.1002/jctb.5689S32843291931

    Subseafloor stratigraphic profiling and soil classification from piezocone tests: A case study in the Gulf of Lion (NW Mediterranean Sea)

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    We show the results provided by piezocone tests in determining the stratigraphic profile and the soil classification of two drilling sites in the outer shelf and the upper slope of the Gulf of Lion, PRGL2 and PRGL1, respectively. Correlations with grain-size data indicate that sleeve friction can be used for profiling fine-grained sediments (site PRGL1), whereas cone tip resistance is the most adequate for sequences made of alternations of coarse- and fine-grained intervals (site PRGL2). Normalized cone resistance and friction ratio proved to be also appropriate for soil stratigraphy as it depicts trends in the coarse fraction of the tested soil. Silts and clays present in similar proportions at site PRGL1 responded to piezocone testing as pure clays usually do. Consequently, classical soil classification methods resulted in erroneous interpretation of these sediments as clays, whereas classification of the heterogeneous deposits at PRGL2 was consistent with the grain size. When tied to a high-resolution seismic reflection profile, the stratigraphy interpreted from the piezocone profile matches with the main seismic sequences and discontinuities defined from seismic stratigraphy analysis. Graded bedding also matches with cone tip resistance and sleeve friction data
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