Características de la canal y de la carne de corderos lechales manchegos : correlaciones y ecuaciones de predicción

Tesis de la Universidad Complutense de Madrid, Facultad de Veterinaria, Departamento de Fisiología (Fisiología Animal), leída el 22-04-2002En el presente trabajo, se han estudiado fundamentalmente las características de las canales de corderos lechales manchegos, así como de su carne y de su grasa, del mismo modo, se han determinado las ecuaciones de predicción de los tejidos de la canal, a partir de los tejidos de las diferentes piezas y de las medidas tomadas en la canal. Se han empleado 49 corderos, 27 machos y 22 hembras, los cuales se sacrificaron a tres pesos 17 a 10 Kg., 16 a 12 Kg. y 16 a 14 Kg. En el estudio realizado para la valoración de la calidad de la canal, se han determinado los rendimientos y las pérdidas. El engrasamiento de la canal se ha determinado mediante medidas objetivos y subjetivas, valorando también la conformación de la canal por medio de apreciación visual y por medidas conformacionales. Se ha estudiado la proporción de piezas y de tejidos de las media canal izquierda, así como la proporción de tejidos de cada pieza. El engrasamiento ha estado principalmente afectado por el sexo de los corderos, mostrando las hembras unos parámetros de engrasamiento superior a los de los nachos. Mientras que la conformación de la canal se encuentra más afectada por el peso de sacrificio, siendo los animales más pesados los mejor conformados. Los animales sacrificados a mayor peso, presentan una menor proporción de hueso en la canal, y en relación a las piezas, estos mismos, muestran una mayor proporción de grasa en el costillar y en la espalda. Las hembras muestran una mayor proporción de grasa de la canal, debido a la mayor precodidad de estas. En relación con los parámetros de calidad de la carne, el peso de sacrificio afecto a la caída de pH y al color de la carne. En cuando a la composición en ácidos grasos, la hembras mostraron una mayor instauración de su grasa. Las ecuaciones obtenidas a partir de los tejidos de las piezas son más precisas que las conseguidas a partir de medidas de engrasamiento y conformación. El costillar para el músculo y la grasa, y la pierna para el hueso han sido las piezas que mejor predicen la proporción de tejidos de la canal. La pierna y la espalda son las piezas que mejor predicen el músculo y el hueso, siendo el costillar en mejor predictor para el tejido graso ambas expresadas en cantidadSección Deptal. de Fisiología (Veterinaria)Fac. de VeterinariaTRUEpu

Características de la canal y de la carne de corderos lechales manchegos : correlaciones y ecuaciones de predicción

En el presente trabajo, se han estudiado fundamentalmente las características de las canales de corderos lechales manchegos, así como de su carne y de su grasa, del mismo modo, se han determinado las ecuaciones de predicción de los tejidos de la canal, a partir de los tejidos de las diferentes piezas y de las medidas tomadas en la canal. Se han empleado 49 corderos, 27 machos y 22 hembras, los cuales se sacrificaron a tres pesos 17 a 10 Kg., 16 a 12 Kg. y 16 a 14 Kg. En el estudio realizado para la valoración de la calidad de la canal, se han determinado los rendimientos y las pérdidas. El engrasamiento de la canal se ha determinado mediante medidas objetivos y subjetivas, valorando también la conformación de la canal por medio de apreciación visual y por medidas conformacionales. Se ha estudiado la proporción de piezas y de tejidos de las media canal izquierda, así como la proporción de tejidos de cada pieza. El engrasamiento ha estado principalmente afectado por el sexo de los corderos, mostrando las hembras unos parámetros de engrasamiento superior a los de los nachos. Mientras que la conformación de la canal se encuentra más afectada por el peso de sacrificio, siendo los animales más pesados los mejor conformados. Los animales sacrificados a mayor peso, presentan una menor proporción de hueso en la canal, y en relación a las piezas, estos mismos, muestran una mayor proporción de grasa en el costillar y en la espalda. Las hembras muestran una mayor proporción de grasa de la canal, debido a la mayor precodidad de estas. En relación con los parámetros de calidad de la carne, el peso de sacrificio afecto a la caída de pH y al color de la carne. En cuando a la composición en ácidos grasos, la hembras mostraron una mayor instauración de su grasa. Las ecuaciones obtenidas a partir de los tejidos de las piezas son más precisas que las conseguidas a partir de medidas de engrasamiento y conformación. El costillar para el músculo y la grasa, y la pierna para el hueso han sido las piezas que mejor predicen la proporción de tejidos de la canal. La pierna y la espalda son las piezas que mejor predicen el músculo y el hueso, siendo el costillar en mejor predictor para el tejido graso ambas expresadas en cantida

Characterization of healthier mixed surimi gels obtained through partial substitution of myofibrillar proteins by pea protein isolates

CRediT authorship contribution statement A. Javier Borderías: Conceptualization, Data curation, Formal analysis, Writing - original draft, Investigation, Methodology, Software, Validation, Visualization, Funding acquisition, Project administration, Supervision. Clara A. Tovar: Conceptualization, Data curation, Formal analysis, Writing - original draft, Investigation, Methodology, Software, Validation, Visualization. Fátima Domínguez-Timón: Conceptualization, Data curation, Formal analysis, Writing - original draft, Investigation, Methodology, Software, Validation, Visualization. M. Teresa Díaz: Conceptualization, Data curation, Formal analysis, Writing - original draft, Investigation, Methodology, Software, Validation, Visualization. Mercedes M. Pedrosa: Conceptualization, Data curation, Formal analysis, Writing - original draft, Investigation, Methodology, Software, Validation, Visualization, Funding acquisition, Project administration, Supervision. Helena M. Moreno: Conceptualization, Data curation, Formal analysis, Writing - original draft, Investigation, Methodology, Software, Validation, Visualization, Supervision, Writing - review & editing.Mixed surimi gels with 8%, 10% and 15% of pea protein isolate (PPI) were made in order to replace part of the myofibrillar proteins with PPI. Phytochemical, mechanical, viscoelastic and structural properties of heat-induced gels were analysed. Resulting gels contained low amounts of galactosides, inositol phosphates, protease inhibitors and phenolic compounds with potential specific health roles. A coupled PPI-myofibrillar matrix was produced on a basis of water binding capacity, electrophoresis profile, reticular flexibility and homogeneous microstructure. Mixed gels were less rigid (lower complex modulus -G*-) and exhibited slightly greater water binding ability than control gel. Addition of 8% and 10% PPI improved conformational flexibility, energy stability and elastic character. In mixed gels with 15% PPI the continuity of the mixed-protein matrix was disrupted and the mechanical and viscoelastic parameters deteriorated. Mixed surimi gels with 8% or 10% were thus more sustainable and healthy for use in meat or seafood analogue processing.Ministerio de Economía y Competitividad (RTA2015-00003-CO2)Depto. de Producción AnimalFac. de VeterinariaTRUEpu

Evaluation of gels made with different commercial pea protein isolate: Rheological, structural and functional properties

The gelling of two commercial pea protein isolates (PPI) at 20% and 23% PPI concentration, and the effect of microbial transglutaminase (-0- and -5- U/g protein), were analysed. The final aim was to get PPI gels with textural properties enough to make meat and seafood analogues. The first PPI (-A-), was made by alkaline solubilization and isoelectric precipitation from pea flour. The second one (-B-), was obtained by aqueous dispersion of the pea flour and concentration of the soluble protein. The water and oil holding capacities of PPI-A suggested a higher degree of protein denaturation which was assessed by Dynamic thermo mechanical analysis (DMTA) and Fourier transform infrared spectroscopy (FTIR). FTIR data showed lower intermolecular β-sheet aggregates in PPI-B gels than in PPI-A. This result was consistent with the reticulated and well-interconnected network from scanning electron microscopy (SEM) of PPI-B gels in line with the higher strain amplitude (γmax), and the lower loss factor (tanδ) in PPI-B gels vs PPI-A gels. The MTGase enzyme significantly improved the structural quality of the PPI-B gels (high Q-factor) at 20% and 23% PPI. For all these reasons PPI B is more suitable for achieving consistent gels as bases for meat and seafood analogues.Depto. de Producción AnimalFac. de VeterinariaTRUEpu

Fasting combined with long catch duration modifies the physio-metabolic response and flesh quality of rainbow trout

Pre-slaughter handling involves fasting fish and catching them, which can affect fish welfare and flesh quality, but few studies have considered their combined effects. In this study, adult rainbow trout (320 ± 10 g average weight) were fasted for 7 days (135.6 degree days) and subjected to a long catch duration (20 min), compared with controls (no fasting or short catch duration). Condition factor, organ weight indexes and carcass yield decreased with fasting but not catch duration. Plasma concentrations of cortisol, glucose and lactate increased after a long catch, while plasma triglycerides decreased with fasting. Liver glycogen concentration was lower in fasted fish, and liver luminosity and chroma were higher after fasting with a long catch. Regarding flesh quality, rigor mortis resolved more slowly and final muscle pH at 48 hr post-mortem was higher for fasted fish with a long catch time. Muscle glycogen concentration was higher in fasted fish, where chroma was also lower. Fasted fish had lower lipid oxidation, but there were no differences in fat content in muscle. Fasted fish with a long catch duration also had less monounsaturated and more saturated fatty acids. In conclusion, a long catch triggered a stress response that had negative effects on flesh quality, independently of fasting.Ministerio de Economía y Competitividad (España)Depto. de Producción AnimalFac. de VeterinariaTRUEpu

Valorisation of an extract from olive oil waste as a natural antioxidant for reducing meat waste resulting from oxidative processes

Spain is the biggest olive oil producer in the world what means that this area is especially affected by olive mill waste pollution. The main system used for extracting olive oil is the continuous two-phase centrifugation system, which generates olive wet cake waste. This wastage has disposal problems due to its phytotoxicity and high moisture content, so strategies for its use and revalorization are needed. One of these strategies is the extraction of bioactive compounds, as is the case of polyphenols present in the waste, which could be used as natural antioxidants in food. This study evaluated the effect of adding an olive waste extract (100, 200 or 400 mg gallic acid equivalents/kg muscle), as a possible natural polyphenol-rich antioxidant on the stability of lamb meat patties enriched with omega-3 fatty acids, and stored in high-oxygen modified atmosphere packs for up to 9 days at 4 °C. Addition of the extract delayed meat discolouration, lipid oxidation (p ≤ 0.001) and protein carbonylation (p ≤ 0.001), and increased loss of thiol groups (p ≤ 0.05) relative to controls. Fish odour (p ≤ 0.01) and flavour (p ≤ 0.05) were lower and odd odour and flavour (p ≤ 0.001) higher in patties with added the extract compared to controls, but the overall liking score was not affected. The addition of the extract resulted in acceptable lamb meat patties (in terms of oxidation) after 6 days of storage, while patties without extract did not. The results pointed out the potential for using olive waste extracts as natural antioxidants in meat products. With this strategy, the olive oil industry would encourage to follow an eco-friendlier olive oil production chain obtaining marketable products from the wastes generated. At the same time, the shelf-life (in terms of oxidation process) of the lamb patties would be increased reducing food wastes at the point-of-sale and at consumer level, which is especially important in a high perishable food such as minced meat products, and reducing the environmental impact that food waste causes along the food supply chain.Depto. de Producción AnimalFac. de VeterinariaTRUEpu

Effect of ice stunning versus electronarcosis on stress response and flesh quality of rainbow trout

In recent years, concerns about fish welfare have increased in aquaculture, most pointedly regarding the slaughter process. Immersion in ice water (live chilling) is still commonly used as a stunning method in salmonids, but can have negative effects on the stress response and flesh quality. A valid alternative is electronarcosis, but the specific details of the intensity and frequency of the current applied depend on the species and size, and little is known about how that may affect fish welfare or product quality. In this study, adult rainbow trout (294 ± 8.44 g average weight) were subjected to three different stunning methods before slaughter: immersion in ice water and electronarcosis at two different current intensities (200 or 400 mA). Electronarcosis caused fish to lose consciousness faster than those live chilled. Plasma concentration of cortisol was lower in fish stunned with 400 mA (400 mA: 5.2 ± 0.67 vs. Ice: 9.1 ± 0.90; 200 mA: 9.3 ± 1.20 ng/ml). Creatine-phosphokinase enzyme levels were higher in ice stunned fish compared to electronarcosis (Ice: 168 ± 2.32 vs. 200 mA: 114 ± 0.89; 400 mA: 104 ± 0.62 U/l). Regarding flesh quality, initial muscle pH was lower in fish stunned by ice immersion than by electronarcosis (Ice: 6.49 ± 0.034 vs. 200 mA: 6.76 ± 0.050; 400 mA: 6.61 ± 0.04), presenting also an earlier onset of rigor mortis. Fish stunned with 400 mA electronarcosis also presented higher levels of muscle glycogen than those stunned with ice water (0.181 ± 0.029 vs. 0.101 ± 0.013 mg/g). In conclusion, electronarcosis is a stunning method that can produce an immediate loss of consciousness in rainbow trout, reducing stress response before slaughter and improving flesh quality (with higher benefits using a current intensity of 400 mA), in contrast to immersion in ice water.Ministerio de Economía y CompetitividadDepto. de Producción AnimalFac. de VeterinariaTRUEpu

Linseed, microalgae or fish oil dietary supplementation affects performance and quality characteristics of light lambs

The aim of this work was to improve the fatty acid profile of meat from light lamb, frequently reared in Spain and in other Mediterranean countries. A total of 44 light lambs fed different n-3 polyunsaturated fatty acids sources were studied: control (C) (palm oil), extruded linseed (L), extruded linseed mixed with microalgae (LM) and fish oil (FO). The productive performance from 14.7 to 26.2 kg of live weights and meat quality characteristics during refrigerated storage were assessed. Lambs fed FO showed lower feed intake (p < 0.001), average daily gain (p < 0.001) and higher feed conversion ratio (p < 0.001) than lambs from the other treatments. Fish oil meat had the lowest (p < 0.01) protein proportion and the highest (p < 0.001) C20:5n-3, C22:5n-3 and C22:6n-3 proportions, while L or LM produced the highest (p < 0.001) C18:3n-3 deposition. Fish oil meat had higher (p < 0.05) L* and lower (p < 0.001) a* than meats from the other treatments. After 7 days of storage, FO meat showed the highest TBARS (p < 0.001), while C meat showed similar value to 0 days of storage. Additionally, FO underwent higher microbial growth after 7 days of storage as compared to the other treatments. Dietary supplementation with L and LM leads to C18:3n-3 meat enrichment and to a microbial load and colour characteristics similar to those of C, without adverse effect on lamb performance. However the use of FO improves the fatty acid profile of meat, but negatively affects lamb performance and meat qualit

Environmental enrichment improves growthandfillet quality in rainbow trout

Background: Some environmental enrichment methods, such as occupational enrichment (OE), can improve fish growth, but little is known about its effects on fillet quality. In this study, we evaluated the effects of OE using underwater currents on different aspects of fillet quality and muscle metabolism in rainbow trout (Oncorhynchus mykiss), before and after a handling procedure (fasting). The trout were placed in groups of 30 in separate tanks in three treatments for 30 days: no artificial currents (CON), randomly fired underwater currents (RFC), and continuous underwater currents (CUC). Additionally, half of the individuals in each treatment were fasted (5 days, 45.2 °C days). Results: Slaughter weight, condition factor, and relative growth were lower in CON fish, indicating a positive effect of OE on growth. Rigor mortis, muscle pH, and muscle glycogen levels were similar among treatments, indicating no effect of OE on classical measures of fillet quality. However, significant differences were found regarding fillet colour and muscle enzymes. The fillets of RFC fish were more salmon-pink in colour, which is favoured by consumers. Also, activity levels of pyruvate kinase and glycogen phosphorylase in muscle were significantly higher in CUC fish, probably due to increased energy demands, as pumps were on continually in that treatment. Conclusion: Overall, RFC fish seemed to have received enough stimulation to improve growth while not being excessive in terms of exhausting the animals (avoiding negative effects on muscle metabolism), whereas OE may have provided a hormetic effect, allowing fish to better adjust to fasting. © 2023 Society of Chemical Industry.Universidad Complutense de MadridBanco SantanderDepto. de Producción AnimalSección Deptal. de Fisiología (Veterinaria)Fac. de VeterinariaTRUEpu

Using Underwater Currents as an Occupational Enrichment Method to Improve the Stress Status in Rainbow Trout

This study investigated the effects of occupational enrichment, specifically underwater currents, on the stress status of rainbow trout (Oncorhynchus mykiss). A total of 540 fish were divided into three groups: control tanks without artificial currents (CO), tanks with randomly fired underwater currents (RFC), and tanks with continuous current throughout the day (CT). After 30 days, half of the fish in each group underwent a 5-day pre-slaughter fasting (5D), while the others were fed until the day before slaughter (0D). Fish in the RFC group exhibited lower levels of plasma cortisol and acetylcholinesterase enzyme activity in hypothalamus and optic tract than other groups, suggesting an improved stress status. RFC group also showed higher levels of non-esterified fatty acids (NEFA) in 5D fish and higher liver glycogen stores, suggesting improved energy reserves. In comparison, the CT group had higher LDH levels, possibly due to their increased swimming activity. The CO group had significantly lower NEFA levels at 5D compared to the RFC group, suggesting lower energy reserves. The RFC fish had darker and yellow-reddish skin and liver color, suggesting an improved stress status and lower lipid reserves, respectively. Overall, although a significant stress response was not observed in fasted individuals, possibly due to the relatively short fasting period, the study suggests that providing occupational enrichment using randomly fired underwater currents for 1 month helped to improve stress status in rainbow trout, indicating that occupational enrichment during the grow-out phase can positively impact the welfare of rainbow trout during routine handling procedures.Universidad Complutense de MadridDepto. de Producción AnimalFac. de VeterinariaTRUEpu