Contribution to the study of lipid composition and nutritional value of intramuscular fat in ruminant meats

Tese de Doutoramento em Ciência e Tecnologia AnimalContribuição para o estudo da composição lipídica e do valor nutricional da gordura intramuscular na carne de ruminantes - A composição em ácidos gordos e o ácido linoleico conjugado (CLA) são temas actuais de grande interesse, com particular relevância para a qualidade da carne e saúde humana. As carnes de ruminantes têm sido consideradas alimentos pouco saudáveis, principalmente devido à sua fracção lipídica com elevada concentração em ácidos gordos saturados. Contudo, as gorduras edíveis dos ruminantes são a principal fonte natural de isómeros CLA, sendo os isómeros bioactivos (c9,t11 e t10,c12) associados a propriedades potencialmente benéficas para a saúde humana. Em Portugal, a informação científica disponível para apoiar a qualidade e a reputação da carne bovina de raças autóctones criadas segundo as especificações de Denominação de Origem Protegida (DOP) continua restrita. Para além disso, os dados disponíveis não permitem ter uma percepção global de como distintos factores influenciam a composição da carne, desde a sua produção até ao consumo. Neste contexto, a nossa investigação foi desenvolvida estudando o efeito dos regimes alimentares dos animais (pastagem×concentrado), processamento tecnológico da carne após o abate (irradiação) e tratamentos térmicos (fervura, microondas e grelhagem), no perfil lipídico, especialmente nos isómeros do CLA, e no valor nutricional de carne de ruminantes. Foram seleccionadas e caracterizadas 4 carnes tradicionais DOP (Carnalentejana, Mertolenga, Barrosã e Arouquesa). Os resultados sugerem que a gordura intramuscular das carnes de novilho relativamente às de vitela, apresentam menor valor nutricional ao longo do ano, devido ao sistema de produção semi-extensivo utilizado nos novilhos. Por sua vez, a Carnalentejana-DOP apresenta uma qualidade nutricional superior comparativamente à carne de vaca de produção intensiva. No sentido de avaliar em detalhe o efeito de diferentes regimes alimentares no valor nutricional dos lípidos da carne, bem como a sua utilidade como discriminantes químicos da origem da carne, realizou-se um ensaio controlado. Os dados obtidos reforçam os resultados anteriores que sugeriam que a carne de animais de pastoreio apresenta melhor qualidade nutricional (teores mais elevados de n-3 PUFA e CLA) do que a carne de animais alimentados a concentrado. Este facto traduz os efeitos benéficos da pastagem no perfil de ácidos gordos da carne. Relativamente às alterações na composição da gordura intramuscular, resultantes do efeito de processamentos seguintes ao abate, a irradiação, uma tecnologia prospectiva para a conservação das carnes, não promoveu modificações significativas. Os tratamentos térmicos, frequentemente utilizados em culinária, induziram um impacto moderado no perfil dos ácidos gordos, como consequência das perdas de humidade e concentração da gordura. Em resumo, a composição lipídica da gordura intramuscular das carnes de bovino DOP estudadas apresenta um valor nutricional acrescentado para os consumidores, considerando os valores de n-3 PUFA, CLA (total e do isómero c9,t11) e da razão n-6/n-3, contribuindo para a sua diferenciação no mercado.RESUMO - Contribuição para o estudo da composição lipídica e do valor nutricional da gordura intramuscular na carne de ruminantes - A composição em ácidos gordos e o ácido linoleico conjugado (CLA) são temas actuais de grande interesse, com particular relevância para a qualidade da carne e saúde humana. As carnes de ruminantes têm sido consideradas alimentos pouco saudáveis, principalmente devido à sua fracção lipídica com elevada concentração em ácidos gordos saturados. Contudo, as gorduras edíveis dos ruminantes são a principal fonte natural de isómeros CLA, sendo os isómeros bioactivos (c9,t11 e t10,c12) associados a propriedades potencialmente benéficas para a saúde humana. Em Portugal, a informação científica disponível para apoiar a qualidade e a reputação da carne bovina de raças autóctones criadas segundo as especificações de Denominação de Origem Protegida (DOP) continua restrita. Para além disso, os dados disponíveis não permitem ter uma percepção global de como distintos factores influenciam a composição da carne, desde a sua produção até ao consumo. Neste contexto, a nossa investigação foi desenvolvida estudando o efeito dos regimes alimentares dos animais (pastagem×concentrado), processamento tecnológico da carne após o abate (irradiação) e tratamentos térmicos (fervura, microondas e grelhagem), no perfil lipídico, especialmente nos isómeros do CLA, e no valor nutricional de carne de ruminantes. Foram seleccionadas e caracterizadas 4 carnes tradicionais DOP (Carnalentejana, Mertolenga, Barrosã e Arouquesa). Os resultados sugerem que a gordura intramuscular das carnes de novilho relativamente às de vitela, apresentam menor valor nutricional ao longo do ano, devido ao sistema de produção semi-extensivo utilizado nos novilhos. Por sua vez, a Carnalentejana-DOP apresenta uma qualidade nutricional superior comparativamente à carne de vaca de produção intensiva. No sentido de avaliar em detalhe o efeito de diferentes regimes alimentares no valor nutricional dos lípidos da carne, bem como a sua utilidade como discriminantes químicos da origem da carne, realizou-se um ensaio controlado. Os dados obtidos reforçam os resultados anteriores que sugeriam que a carne de animais de pastoreio apresenta melhor qualidade nutricional (teores mais elevados de n-3 PUFA e CLA) do que a carne de animais alimentados a concentrado. Este facto traduz os efeitos benéficos da pastagem no perfil de ácidos gordos da carne. Relativamente às alterações na composição da gordura intramuscular, resultantes do efeito de processamentos seguintes ao abate, a irradiação, uma tecnologia prospectiva para a conservação das carnes, não promoveu modificações significativas. Os tratamentos térmicos, frequentemente utilizados em culinária, induziram um impacto moderado no perfil dos ácidos gordos, como consequência das perdas de humidade e concentração da gordura. Em resumo, a composição lipídica da gordura intramuscular das carnes de bovino DOP estudadas apresenta um valor nutricional acrescentado para os consumidores, considerando os valores de n-3 PUFA, CLA (total e do isómero c9,t11) e da razão n-6/n-3, contribuindo para a sua diferenciação no mercado.This work was co-financed by Centro de Investigação Interdisciplinar em Sanidade Animal (Project CIISA/52.Carne-Bioactivos) da Faculdade de Medicina Veterinária da Universidade Técnica de Lisboa and Fundação para a Ciência e a Tecnologia (POCTI/CVT/2002/44750) and Ministério da Agricultura (AGRO/2003/512)

Binomial effects of high isostatic pressure and time on the microbiological, sensory characteristics and lipid composition stability of vacuum packed dry fermented sausages “chouriço”

The effect of high pressure processing (HPP), at different combinations of pressure and time, on dry fermented sausages (DFS)was evaluated by chemical, microbiological and sensory analyses. Lipid composition and stability were also assessed. HPP (N400MPa and longer than 154 s) produced a reduction in spoilage microbiota,without negative effect on fermentative microbiota, that will be able to continue their role. Total fatty acids and lipid stability were not affected. Only a small effect on fatty acid (FA) composition was observed. Nutritional value of the lipid fraction was only affected by the ratio n−6/n−3 FA. Treatments at 400MPa for 154 s or 960 s resulted in DFS being detected as different from control by sensory analysis. Those differences did not depreciate the product; on the contrary it seems to improve the bright aspect of the whole sausage, the cohesion and firmness and the correctly dried aspect of slices. Industrial relevance: Dry fermented meat sausages are very popular ready-to-eat meat based products. This study assesses the effects of HPP on this much appreciated traditional products. The results showed that HPP can be successfully applied to theseMediterranean fermented products without losses of sensory and nutritional characteristics. The modelling and optimization of the HPP process applied on dry fermented sausages demonstrated in this study are an advantage to industry efficiency. The utilisation of HPP by the industry can significantly increase dry fermented meat sausage shelf life and safety, providing it an opportunity to reach the global market

Procjena utjecaja visokoga tlaka na hidrolizu naringina u soku grejpfruta pomoću naringinaze imobilizirane u kapsulama kalcijeva alginata

The reduction of bitterness in citrus juices would increase their acceptance by the consumer. This reduction in grapefruit juices can be achieved as a result of an enzymatic process, with improved commercial value and maintenance of health properties. The use of a cheap, simple and effective immobilisation method combined with high pressure can be a key asset in the debittering of citrus juices. The aim of this study is the debittering of grapefruit juice under high pressure, with naringinase immobilized in calcium alginate beads. Naringinase, an α-rhamnopyranosidase, hydrolyzes naringin (a flavanone glycoside and primary bitter component in grapefruit juice) to naringenin, which is tasteless. High pressure can activate or inhibit enzymatic activities depending on the proteins and conditions. The hydrolysis of naringin was first evaluated in model solution (acetate buffer 0.02 M, pH=4.0) and then in grapefruit juice. In model solution, at 160 MPa and 37 °C, a 50 % increase in the concentration of reducing sugars was obtained when compared to the reaction at atmospheric pressure. The higher naringenin concentration (33 mg/L) was obtained at 54 °C under high pressure of 200 MPa, which corresponds to a naringin reduction of 72 % in model solution, while at atmospheric pressure (0.1 MPa), the naringin reduction was only 35 %. The decrease in naringin content can be directly correlated with the reduction in bitterness. From the concentration of residual naringin, the percentage of reduction in bitterness was evaluated. In grapefruit juice, a debittering of 75 % occurred with a pressure of 160 MPa at 37 °C for 20 minutes.Smanjenjem gorčine sokova citrusa povećala bi se njihova prihvatljivost za potrošače. Gorčina soka grejpfruta može se smanjiti enzimskim procesom koji poboljšava komercijalnu vrijednost soka, a ne smanjuje njegov pozitivan utjecaj na zdravlje. Uporaba jeftinih, jednostavnih i djelotvornih metoda imobilizacije, kombiniranih uz primjenu visokoga tlaka, ključni su za odgorčavanje sokova citrusa. Svrha je ovog istraživanja smanjiti gorčinu soka grejpfruta primjenom visokoga tlaka i naringinaze imobilizirane u kapsulama kalcijeva alginata. Naringinaza, tj. α-ramnopiranozidaza, hidrolizira naringin (flavanon glikozida što je osnovna gorka komponenta soka grejpfruta) u naringenin koji nema okus. Visoki tlak može aktivirati ili inhibirati aktivnost enzima ovisno o sastavu proteina i uvjetima hidrolize. U radu je najprije istražena hidroliza naringina u modelnoj otopini (acetatni pufer 0,02 M; pH=4,0), a zatim u soku grejpfruta. U modelnoj je otopini pri 160 MPa i 37 °C postignuto 50 %-tno povećanje koncentracije reducirajućih šećera, u usporedbi s reakcijom pri atmosferskom tlaku. Veća koncentracija naringenina (33 mg/L) postignuta je pri 54 °C i visokom tlaku od 200 MPa, što odgovara 72 %-tnoj redukciji narinigina u modelnoj otopini, dok je pri atmosferskom tlaku (0,1 MPa) redukcija naringina iznosila samo 35 %. Smanjenje koncentracije naringina može se povezati sa smanjenjem gorčine soka, tako da je postotak smanjenja procijenjen prema koncentraciji preostalog naringina. U soku grejpfruta smanjenje gorčine od 75 % postignuto je pri tlaku od 160 MPa, na 37 °C, tijekom 20 minuta

Procjena utjecaja visokoga tlaka na hidrolizu naringina u soku grejpfruta pomoću naringinaze imobilizirane u kapsulama kalcijeva alginata

The reduction of bitterness in citrus juices would increase their acceptance by the consumer. This reduction in grapefruit juices can be achieved as a result of an enzymatic process, with improved commercial value and maintenance of health properties. The use of a cheap, simple and effective immobilisation method combined with high pressure can be a key asset in the debittering of citrus juices. The aim of this study is the debittering of grapefruit juice under high pressure, with naringinase immobilized in calcium alginate beads. Naringinase, an α-rhamnopyranosidase, hydrolyzes naringin (a flavanone glycoside and primary bitter component in grapefruit juice) to naringenin, which is tasteless. High pressure can activate or inhibit enzymatic activities depending on the proteins and conditions. The hydrolysis of naringin was first evaluated in model solution (acetate buffer 0.02 M, pH=4.0) and then in grapefruit juice. In model solution, at 160 MPa and 37 °C, a 50 % increase in the concentration of reducing sugars was obtained when compared to the reaction at atmospheric pressure. The higher naringenin concentration (33 mg/L) was obtained at 54 °C under high pressure of 200 MPa, which corresponds to a naringin reduction of 72 % in model solution, while at atmospheric pressure (0.1 MPa), the naringin reduction was only 35 %. The decrease in naringin content can be directly correlated with the reduction in bitterness. From the concentration of residual naringin, the percentage of reduction in bitterness was evaluated. In grapefruit juice, a debittering of 75 % occurred with a pressure of 160 MPa at 37 °C for 20 minutes.Smanjenjem gorčine sokova citrusa povećala bi se njihova prihvatljivost za potrošače. Gorčina soka grejpfruta može se smanjiti enzimskim procesom koji poboljšava komercijalnu vrijednost soka, a ne smanjuje njegov pozitivan utjecaj na zdravlje. Uporaba jeftinih, jednostavnih i djelotvornih metoda imobilizacije, kombiniranih uz primjenu visokoga tlaka, ključni su za odgorčavanje sokova citrusa. Svrha je ovog istraživanja smanjiti gorčinu soka grejpfruta primjenom visokoga tlaka i naringinaze imobilizirane u kapsulama kalcijeva alginata. Naringinaza, tj. α-ramnopiranozidaza, hidrolizira naringin (flavanon glikozida što je osnovna gorka komponenta soka grejpfruta) u naringenin koji nema okus. Visoki tlak može aktivirati ili inhibirati aktivnost enzima ovisno o sastavu proteina i uvjetima hidrolize. U radu je najprije istražena hidroliza naringina u modelnoj otopini (acetatni pufer 0,02 M; pH=4,0), a zatim u soku grejpfruta. U modelnoj je otopini pri 160 MPa i 37 °C postignuto 50 %-tno povećanje koncentracije reducirajućih šećera, u usporedbi s reakcijom pri atmosferskom tlaku. Veća koncentracija naringenina (33 mg/L) postignuta je pri 54 °C i visokom tlaku od 200 MPa, što odgovara 72 %-tnoj redukciji narinigina u modelnoj otopini, dok je pri atmosferskom tlaku (0,1 MPa) redukcija naringina iznosila samo 35 %. Smanjenje koncentracije naringina može se povezati sa smanjenjem gorčine soka, tako da je postotak smanjenja procijenjen prema koncentraciji preostalog naringina. U soku grejpfruta smanjenje gorčine od 75 % postignuto je pri tlaku od 160 MPa, na 37 °C, tijekom 20 minuta

Combined efects of dietary Laminaria digitata with alginate lyase on plasma metabolites and hepatic lipid, pigment and mineral composition of broilers

Research Areas: Veterinary SciencesABSTRACT - Background: The Laminaria digitata is an abundant macroalga and a sustainable feedstock for poultry nutrition. L. digitata is a good source of essential amino acids, carbohydrates and vitamins, including A, D, E, and K, as well as triacylglycerols and minerals, in particular iron and calcium. However, the few studies available in the literature with broilers document the application of this macroalga as a dietary supplement rather than a feed ingredient. No study has addressed up until now the efects of a high-level incorporation (>2% in the diet) of L. digitata on plasma biochemical markers and hepatic lipid composition, as well as minerals and pigments profle in the liver of broilers. Our experimental design included one hundred and twenty Ross 308 male birds contained in 40 wired-foor cages and distributed to the following diets at 22days of age (n=10) for 15days: 1) a corn-soybean basal diet (Control); 2) the basal diet plus 15% of L. digitata (LA); 3) the basal diet plus 15% of L. digitata with 0.005% of Rovabio® Excel AP (LAR); and 4) the basal diet plus 15% of L. digitata with 0.01% of the recombinant CAZyme, alginate lyase (LAE).info:eu-repo/semantics/publishedVersio

Impact of dietary Chlorella vulgaris and carbohydrate-active enzymes incorporation on plasma metabolites and liver lipid composition of broilers

Research Areas: Veterinary SciencesBackground: Chlorella vulgaris has been proposed as a sustainable green feedstock in poultry nutrition due to its ease of cultivation, minimal environmental impact and balanced nutritional composition. However, the majority of studies documents the use of C. vulgaris as a dietary supplement in broilers instead of a feed ingredient. To the best of our knowledge, no report has shown the effect of a high-level incorporation (>2 % in the diet) of C. vulgaris on plasma metabolites and hepatic lipid composition of broilers. One hundred and twenty Ross 308 male birds were housed in 40 wired-floor cages and randomly distributed by the following experimental diets at 22 days of age (n = 10) during 15 days: (1) a corn-soybean meal based diet (control); (2) based diet with 10% of C. vulgaris; (3) diet 2 supplemented with 0.005% Rovabio® Excel AP; and (4) diet 2 supplemented with 0.01% of a pre-selected four-CAZyme mixture. Results: The inclusion of C. vulgaris at 10% in the diet, regardless of the presence of exogenous CAZymes, changed plasma metabolites but did not compromise broilers growth. Plasma total lipids increased in broilers fed C. vulgaris combined with the two feed CAZymes (p < 0.001) compared with the control diet. Moreover, the supplementation with Rovabio® increased total cholesterol and LDL-cholesterol, while the addition of the four-CAZyme mixture increased triacylglycerols, VLDL-cholesterol and ALP activity. In opposition, HDL-cholesterol levels decreased in broilers fed microalga alone (p = 0.002). Regarding hepatic composition, the inclusion of C. vulgaris in broiler diets, individually or combined with exogenous CAZymes, had a minor effect on fatty acids but improved the n-6/n-3 ratio and total carotenoids. Conclusions: In summary, the inclusion of a high level (10%) of C. vulgaris in broiler´s diet, regardless of the presence of exogenous CAZymes, improved hepatic antioxidant composition and did not impair broiler’s performance. In addition, the feed supplementation with CAZymes increased broilers lipemia. Therefore, dietary C. vulgaris at this incorporation level seems to be safe for animal health and do not compromise performance traits, with no need of CAZymes supplementation.info:eu-repo/semantics/publishedVersio

An individual alginate lyase is effective in the disruption of Laminaria digitata recalcitrant cell wall

Research Areas: Science & Technology - Other TopicsIn the present study, 199 pre-selected Carbohydrate-Active enZymes (CAZymes) and sulfatases were assessed, either alone or in combination, to evaluate their capacity to disrupt Laminaria digitata cell wall, with the consequent release of interesting nutritional compounds. A previously characterized individual alginate lyase, belonging to the family 7 of polysaccharide lyases (PL7) and produced by Saccharophagus degradans, was shown to be the most efcient in the in vitro degradation of L. digitata cell wall. The alginate lyase treatment, compared to the control, released up to 7.11 g/L of reducing sugars (p< 0.001) and 8.59 mmol/100 g dried alga of monosaccharides (p< 0.001), and reduced cell wall fuorescence intensity by 39.1% after staining with Calcofuor White (p= 0.001). The hydrolysis of gel-forming polymer alginate by the alginate lyase treatment could prevent the trapping of fatty acids and release benefcial monounsaturated fatty acids, particularly 18:1c9 (p < 0.001), to the extracellular medium. However, no liberation of proteins (p > 0.170) or pigments (p > 0.070) was observed. Overall, these results show the ability of an individual alginate lyase, from PL7 family, to partially degrade L. digitata cell wall under physiological conditions. Therefore, this CAZyme can potentially improve the bioavailability of L. digitata bioactive compounds for monogastric diets, with further application in feed industry.info:eu-repo/semantics/publishedVersio

Effect of dietary conjugated linoleic acid isomers on water and glycerol permeability of kidney membranes

NOTICE: this is the author’s version of a work that was accepted for publication in Biochemical and Biophysical Research Communications. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Biochemical and Biophysical Research Communications. May 2009; 383(1): 108-112.Conjugated linoleic acid (CLA) refers to a group of positional and geometrical isomers of linoleic acid in which the double bonds are conjugated. Dietary CLA has been associated with various health benefits although details of its molecular mode of action remain elusive. The effect of CLA supplemented to palm oil-based diets in Wistar rats, as a mixture of both or isolated c9,t11 and t10,c12 isomers, was examined on water and glycerol membrane permeability of kidney proximal tubule. Although water permeability was unaltered, an increase in glycerol permeability was obtained for the group supplemented with CLA mixture, even though the activation energy for glycerol permeation remained high. This effect was correlated with an increased CLA isomeric membrane incorporation for the same dietary group. These results suggest that diet supplementation with CLA mixture, in contrast to its individual isomers, may enhance membrane fluidity subsequently raising kidney glycerol reabsorption

Effect of high hydrostatic pressure challenge on biogenic amines, microbiota, and sensory profile in traditional poultry- and pork-based semidried fermented sausage

Research Areas: Food Science & TechnologyThe processing of traditional poultry- and pork-based semidried fermented smoked sausages needs to bemodernized to improve product quality and further extend its shelf life. The aim of the present study was to applydifferent combinations of high pressure (300 to 600 MPa) and time (154 to 1,800 s) on the sausages using an experimentaldesign based on response surface methodology. The chemical, microbial, and sensory characteristics of sausages treatedwith high-pressure processing (HPP) were investigated. HPP application to semidried fermented sausages resulted incolor changes, which could be dependent on the ingredients, formulation, and smoking conditions used. Nevertheless,none of the HPP treatments applied resulted in detectable changes in sensory properties, as tested in a triangle test andconfirmed by the analysis of focus groups assessment. Significant differences were detected for lactic acid bacteria (LAB)counts from 344 MPa and 1,530 s onward, with a marked decrease for the combination of 600 MPa and 960 s (P<0.05).Coagulase-negativestaphylococcishowed higher tolerance to the increase in pressure than LAB. HPP induced a microbialreduction onEnterobacteriaceae, molds, and yeasts, minimizing the production of the main biogenic amines. However,the polyamines (spermine and spermidine) increased since their metabolic use by microorganisms did not occur. Giventhe reduction of the main spoilage microbial indicators with no detectable sensory changes observed with the binomialcondition of 600 MPa and 960 s, this was chosen as the optimal combination to be further applied.info:eu-repo/semantics/publishedVersio

Quality Traits and Nutritional Value of Pork and Poultry Meat from Animals Fed with Seaweeds

ReviewSeaweeds have caught the attention of the scientific community in recent years. Their production can mitigate the negative impact of anthropogenic activity and their use in animal nutrition reduces the dependency on conventional crops such as maize and soybean meal. In the context of monogastric animals, novel approaches have made it possible to optimise their use in feed, namely polysaccharide extraction, biomass fermentation, enzymatic processing, and feed supplementation with carbohydrate-active enzymes (CAZymes). Their bioactive properties make them putative candidates as feed ingredients that enhance meat quality traits, such as lipid oxidation, shelf-life, and meat colour. Indeed, they are excellent sources of essential amino acids, polyunsaturated fatty acids, minerals, and pigments that can be transferred to the meat of monogastric animals. However, their nutritional composition is highly variable, depending on species, harvesting region, local pollution, and harvesting season, among other factors. In this review, we assess the current use and challenges of using seaweeds in pig and poultry diets, envisaging to improve meat quality and its nutritional valueinfo:eu-repo/semantics/publishedVersio