Enhancing bioactive fatty acids of the meat from lambs reared in intensive systems through nutritional modulation

Tese de Doutoramento em Ciências Veterinárias, especialidade de Produção [email protected] meats are characterized by being rich in saturated fatty acids (SFA), particularly, and low in polyunsaturated fatty acids (PUFA), which is regarded as disadvantageous for humans. However, ruminant meats are also the dietary source of some bioactive health benefit fatty acids, including conjugated linoleic acid isomers (CLA) and long chain polyunsaturated fatty acids from the n-3 series (n-3 LC-PUFA). In the present thesis we have explored three nutritional strategies to improve the fatty acid (FA) profile of lamb meat, in order to maximize CLA and n-3 LC-PUFA content. Two experiments were conducted to evaluate the effects on lipid metabolism and fatty composition of meat from lambs intensively fattened of the i) dietary inclusion of Cistus ladanifer L. (C. ladanifer); ii) dietary supplementation with vegetable oils and iii) replacement of cereal grains by dehydrated citrus pulp (DCP) in diets. A global evaluation of the effects of the dietary treatments on production, meat quality and meat lipid composition, was achieved by recording the productive performance of lambs, carcasses composition, and determining analytically the fatty acid composition, oxidative stability and organoleptic quality of meat. Moreover, the expression of genes encoding Δ5-, Δ6- and Δ9-desaturases (FADS1, FADS2 and SCD) in longissimus muscle was also assessed. The first experiment, involved 54 Merino Branco lambs, and evaluated the effects of the dietary inclusion of C. ladanifer (rockrose) (Cistus) and of the lipid supplementation with a blend of linseed and soybean oil (2:1 vol/vol). Nine diets were formulated resulting from the combination between 3 levels of C. ladanifer inclusion (50, 100 and 200g/kg of dry matter (DM)) and 3 levels of oil supplementation ((0, 40 e 80g/kg DM)). On second experiment, 32 Merino Branco lambs were fed using diets containing 60g/kg DM of soybean oil and 50% of dehydrated lucerne, and there were evaluated the effects of C. ladanifer inclusion (0 vs 150g/kg) DM) and the replacement of cereal grains by DCP in the diets. On the first experiment, the diets did not affect animal´s growth. Lipid suplementation reduced DM intake, muscle proportion in the carcass and increased kidney knobb channel fat. Meat chemical and physical parameters were not influenced by the diets. The level of 100g/kg of C. ladanifer inclusion improved meat oxidative stability during 7 days of storage. The perception of off-flavours was higher and meat overall acceptability by the sensory panel was reduced with suplementation 8% oil blend. The increasing inclusion of C. ladanifer and oil in the diet act sinergetically on the 10t-18:1 in meat. C. ladanifer increased total amount and proportion of trans monoinsaturated FA (trans MUFA) and reduced the proportions of eicosapentaenoic (EPA) and docosapentaenoic (DPA) acids. The dietary suplementation with vegetable oil blend was a good strategy to improve nutritional value of meat, enhancing total amount of linolenic acid (18:3 n-3) and of n-3 PUFA, and reducing the proportion of SFA, which it was followed by an increment of the proportion of PUFA on lipid profile of intramuscular fat (IMF). The expression of the SCD mRNA increased with C. ladanifer but it was not correlated with the concentration of the Δ9-desaturase FA products. On the second experiment, DM intake increased with C. ladanifer, althought growth was not influenced by diets. Carcass composition was not affected by the dietary treatments, but an interaction between C. ladanifer and DCP was observed for dressing percentage. Dietary factors did not influence muscular pH, cooking losses, meat color and oxidative stability during storage. However, meat shear force increased with the adition of C. ladanifer to diets. Meat tenderness and juiciness were both reduced by C. ladanifer and DCP, but only C. ladanifer reduced meat overall acceptability assessed by the sensory panel. The inclusion of C. ladanifer to 1:1 forage to concentrate ratio diets enriched with soybean oil, reduced the occurrence of trans-10 shift, but did not increase 11t-18:1 and 9c,11t-18:2 concentrations on meat lipids. Trans fatty acids (TFA) were reduced by C. ladanifer inclusion in diets. Dehydrated citrus pulp improved meat nutritional value by increasing 18:3 n-3.RESUMO - Enriquecimento em ácidos gordos bioactivos da carne de borrego de sistema intensivo através da modulação nutricional do metabolismo lipídico - A carne de ruminantes caracteriza-se por ser particularmente rica em ácidos gordos saturados (AGS) e pobre em ácidos gordos poliinsaturados (AGPI), o que é considerado como negativo para a dieta humana. Contudo, é também uma importante fonte de alguns ácidos gordos bioactivos benéficos para a saúde, como os isómeros conjugados do ácido linoleico (CLA) e ácidos gordos poliinsaturados de cadeia longa da família n-3 (n-3 CL-AGPI). Na presente tese explorámos três estratégias nutricionais de modo a melhorar o perfil lipídico da carne de borrego através do aumento do seu conteúdo em CLA e em n-3 n-3 CL-AGPI. Foram realizadas duas experiências nas quais os efeitos i) da inclusão de Cistus ladanifer L. (esteva); ii) da suplementação lipídica com óleos vegetais e iii) da substituição dos grãos de cereais por polpa de citrínos desidratada (PCD) no metabolismo lipídico e na composição em ácidos gordos da carne de borrego de sistema intensivo de engorda foram avaliados. A avaliação integrada dos efeitos dos tratamentos no desempenho produtivo, foi efectuada registando-se a ingestão de matéria seca (MS), ganho médio diário e composição das carcaças dos borregos, assim como a qualidade física e sensorial da carne e a sua composição em ácidos gordos e níveis de expressão dos genes que codificam para as Δ5, Δ6 e Δ9-desaturases (FADS1, FADS2 e SCD mRNAs). No primeiro ensaio, que envolveu 54 borregos Merino Branco avaliámos a inclusão, na dieta, de Cistus ladanifer (esteva), e da suplementação lipídica constituída por uma mistura de óleo de linho e de soja (2:1 vol/vol). Para tal foram formuladas 9 dietas que resultaram da combinação entre 3 níveis de inclusão de C. ladanifer (50, 100 e 200g/kg de matéria seca (MS)) e 3 níveis de suplementação lipídica (0, 40 e 80g/kg de MS). No segundo ensaio, utilizaram-se 32 borregos alimentados com dietas contendo 50% de luzerna desidratada e 60g/kg MS de óleo de soja, e avaliaram-se os efeitos da inclusão de C. ladanifer (0 vs 150g/kg) de MS) e da substituição dos grãos de cereais por polpa de citrínos desidratada (PCD) nas dietas. No primeiro ensaio, os tratamentos não afectaram o crescimento dos animais. O óleo reduziu a ingestão de MS, a proporção de músculo da carcaça e aumentou a quantidade de gordura pélvica e renal. As caraterísticas físicas e químicas da carne não foram afectadas pelas dietas. O nível de 100g/kg de esteva melhorou a estabilidade oxidativa da carne durante o armazenamento de 7 dias. A percepção de off-flavours foi superior e a aceitação global por parte do painel de provadores foi inferior para a suplementação com 8% de óleo. A inclusão de C. ladanifer potenciou o aumento de 10t-18:1 na carne induzido pelo óleo. Com a inclusão de C. ladanifer nas dietas aumentou a quantidade total e proporção de ácidos gordos monoinsaturados trans (TransAGMI) e diminuiram as proporções dos ácidos eicosapentaenoico (EPA) e docosapentaenoico (DPA). A suplementação das dietas com a mistura de óleos vegetais foi uma boa estratégia para melhorar o valor nutricional da carne, permitindo um aumento da quantidade total de ácido linolénico (18:3 n-3) e n-3 AGPI, e a redução da proporção de AGS acompanhada de um aumento da proporção de AGPI no perfil lipídico da gordura intramuscular. A expressão do mRNA do gene SCD aumentou com a inclusão de C. ladanifer nas dietas. No segundo ensaio, a ingestão de MS aumentou com a inclusão de C. ladanifer, embora o crescimento não tenha sido influenciado pelas dietas. A composição da carcaça não foi afectada pelos tratamentos, mas verificou-se uma interacção entre a inclusão de esteva e a de PCD que afectou o rendimento da carcaça. Os factores em estudo não influenciaram o pH muscular, as perdas por cozedura, a cor da carne e a sua estabilidade oxidativa. No entanto, ocorreu um aumento da força de corte da carne com a adição de C. ladanifer às dietas. A tenrura e a suculência da carne sofreram uma diminuição com a inclusão de C. ladanifer e de PCD nas dietas, no entanto a aceitação global da carne pelo painel de provadores apenas foi diminuída com C. ladanifer. A inclusão de C. ladanifer a dietas com uma relação de forragem: concentrado de 1:1 e enriquecidas com óleo de soja, reduziu a ocorrência do trans-10 shift, embora não tenha aumentado os teores de 11t-18:1 e de 9c,11t-18:2 na fracção lipídica da carne. O total de ácidos gordos trans (AGT) na carne foi reduzido pela inclusão de esteva nas dietas. A PCD melhorou o valor nutricional da gordura da carne de borrego, aumentando a concentração em 18:3 n-3

Innovative concepts of Integrated Solar Combined Cycles (ISCC) using a Solid Oxide Fuel Cell (SOFC)

Concentrating Solar Power (CSP) is one of the most promising ways for electricity production of the upcoming years with high penetration of intermittent renewable energy sources such as wind and solar-photovoltaics. This is due to the fact that CSP when coupled to Thermal Energy Storage (TES) system enables large, inexpensive and flexible energy dispatch, which contributes to energy grid stabilization. At the same time, TES allows for steady operation of the power block by reducing undesirable fluctuations due to weather transient conditions and increasing the number of hours that the power block operates at design conditions 1. Despite the abovementioned advantages of CSP systems, a step further is needed for increase overall system efficiency and decrease CO2 emissions. Several studies have been performed considering high efficiency plant layouts such as combined cycle. For the latter, several works have been investigated about solar integration of combined cycle using parabolic trough and solar tower technologies. In both cases, solar energy was used for water/steam preheating and evaporation steps of the Rankine cycle in combination with the exhaust gases of fossil-fuel gas turbine engine. However, no research has been performed considering ISCC coupled with a Solid Oxide Fuel Cell (SOFC). In this research, two innovative layouts of ISCC power plants will be analyzed. First considers a ISCC based on solar tower and second a ISCC with a parabolic trough collector field coupled to the Heat Recovery Steam Generator (HRSG). The objective of this research is analyze the energy behavior of both layouts, selecting the best ISCC scheme to be coupled with a SOFC. The simulations will be performed using Thermoflex software. In both layouts, a SOFC is introduced before the combustion chamber at the topping cycle, and a Rankine cycle (bottoming cycle) with 2 pressures is considered.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Linguistic perceptions of Irish English in nineteenth-century emigrant letters : a micro-perspective analysis of John Kerr's letters.

In this paper we look at the real voices of Irish English speakers in the nineteenth century. By turning to the Corpus of Irish English Correspondence (McCafferty & Amador-Moreno, 2012), we analyse the perceptions that letter writers had of their own language use. We apply a micro-perspective analysis to the language of John Kerr, an Irish emigrant to America, in his letters to his uncle James Graham of Newpark (Co. Antrim, N. Ireland). We examine Kerr’s incisive comment on language use alongside metacommentary found in different Late Modern works, including dictionaries, essays on Irish English, as well as contemporary fictional representations of the variety of English spoken in Ireland during this period. Through this small batch of letters, we explore how the real voices of Irish English speakers echoed an enregistered Irish repertoire that may have raised awareness shaping their perceptions of their own dialect

Estimación de la composición florística y carbono almacenado en sistemas agroforestales con café (Coffea arabica L.) en comarca Loma de Cafen, Boaco, 2021

En Nicaragua el café (Coffea arabica L.), aporta aproximadamente 400 millones de dólares en divisas equivalente al 33 % de las exportaciones agropecuarias y cerca de 400 000 empleos durante la cosecha. Se describió las características generales de los sistemas agroforestales con café, identificó la compisicion florística arbórea y determinó el carbono almacenado en suelo, arboles, mantillo y arbustos de café en comarca Loma de Cafen, Boaco, 2021. La investigación fué no experimental cuyo proceso metodológico constó de tres fases: planificación, operativa y analisis de datos e interpretación de resultados. Se utilizaron parcelas anidadas de 10 x10 m, 5 x 5 m y un m2 al centro del Sistema Agroforestal. Se trabajó con pequeños productores de café de 0.35 a 2.45 ha, con ocho a dos personas por hogar, todos utilizan la variedad catimor, suelos arcillosos de pH moderadamente ácidos y altos en materia orgánica. Se identificaron 85 árboles en 16 familias y 22 especies con predominio de Cordia alliodora con una abundancia de 17 individuos, Guazuma ulmifolia 11 y Citrus sinensis nueve; bajo índice de diversidad según Shannon Wiener con un rango de entre 1.15 a 1.93 y la formación de tres grupos según el índice de similitud de Bray Curtis, el de mayor similitud formado por las fincas San Antonio y El Pogreso que comparten cinco de las 22 especies, seguido por las fincas Cielo Azul, Las Miradas y Divino Niño compartiendo de una a cuatro especies y el tercer grupo formado por las fincas El Chilamate y La Herradura compartiendo una especie. El suelo fue el componente que más carbono almacenó con un promedio de 81.35, seguido de árboles 10.18, mantillo 1.9 y arbustos de café 1.25 t ha-1 C. Se concluye que se investigo en fincas de pequeños productores de café bajo sombra con sulos ácidos, pero altos en materia orgánica con baja biodiversidad arbórea y formación de tres grupos según índice de similitud de Bray Curtis, que el suelo es quien mas carbono almacena seguido de árboles, arbustos de café y mantillo, en promedio los SAF almacenan 95.1 con un máximo de 124.4 y mínmo de 58.63 t ha-1 C. Con respecto a carbono almacenado el análisis de componentes principales mostró relación positiva entre el suelo y su materia orgánica; entre árboles y arbustos de café con sus diámetros y alturas y, el mantillo con las dimensiones de los árboles

Value of Travel Time Savings for University Students and Preference Heterogeneity

This paper examines the sensitivity of value of travel time savings (VTTS) to assumptions on individual preferences in a random utility discrete choice framework. Preferences heterogeneity is incorporated by introducing random parameters and by interacting characteristics of travel modes with characteristics of the individual. The data set is a revealed preference survey on student travel mode choice. The results indicate that there is a systematic influence of gender on VTTS and additional heterogeneity is explained by unobserved characteristics. The evidence also suggests model specifications that impose preferences homogeneity tend to produce lower estimates of VTTS compared with more flexible structures that allow random variation of parameters over individuals. However, the degree of underestimation seems to be context dependent..Random utility discrete choice models, preference heterogeneity, subjective value of travel time, random parameter logit.