8 research outputs found

    RAPID AND CONVERGENT ASSEMBLY OF NATURAL BENZO[c]PHENANTHRIDINES BY PALLADIUM/NORBORNENE CATALYSIS

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    A straightforward total synthesis of a small panel of natural benzo[c]phenanthridines is described. The selective coupling of an aryl triflate with a bromobenzylamine by means of palladium/norbornene joint catalysis and a sequential transfer hydrogenation deliver these alkaloids in one pot. Dihydrophenanthridines initially formed undergo dehydrogenation smoothly while norbornene acts both as a catalyst for their assembly and as a sacrificial olefin in their dehydrogenatio

    Fatty acid and vitamin E composition of intramuscular fat in cattle reared in different production systems

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    The aim of this study was to evaluate the fatty acid composition of intramuscular fat and the vitamin E content of beef from different production systems. Four cattle production systems were used cattle reared under intensive conditions and fed concentrate (INT1) from Spain, cattle raised at pasture and supplemented with concentrate (SUP1) from the United Kingdom, cattle raised at pasture and on corn silage (SUP2) from Germany and cattle reared under extensive conditions slaughtered at two and three years old (EXT2 and EXT3) from Uruguay. The highest proportion and content (mg per 100 g of muscle) of linoleic acid (C182n-6) and arachidonic acid (C204n-6) and the lowest saturated fatty acids (SFA) was found in INT1 beef. In contrast, beef reared under extensive conditions showed the highest proportion and content of linolenic acid (C183n-3), docosapentaenoic acid (DPA, C225n-3) and eicosapentaenoic acid (EPA, C205n-3), and SUP1 and SUP2 beef showed the highest level of palmitic acid (C160) and SFA. Beef from intensive system (INT1) had the lowest P/S (PUFA/SFA) ratio, whereas beef from extensive system (EXT2 and EXT3) had the lowest n-6/n-3 ratio. The results of the PCA (principal components analysis) of fatty acid composition showed that beef from intensive system (INT1) was clearly differentiated from the other meats and was located with the C18:2n-6 and C20:4n-6 and the n-6/n-3 ratio. EXT2 and EXT3 beef were located with C18:3n-3 and long chain fatty acids. Beef from extensive systems had the highest concentration of vitamin E (3.91 mg α-tocopherol/kg muscle). © 2009

    Fatty acid composition of meat from typical lamb production systems of Spain, United Kingdom, Germany and Uruguay

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    The fatty acid composition of commercial lambs from different production systems of Spain, Germany, United Kingdom and of two types of Uruguayan lambs (heavy and light) was studied. Concentrate fed lambs, as Spanish lambs, displayed the highest proportions of linoleic acid (C182), while Uruguayan lambs, reared under extensive grazing conditions, showed the highest proportions of linolenic acid (C183), due to the great concentration of this fatty acid in grass. German and British lambs, which were fed grass and concentrate, displayed intermediate proportions of linolenic acid (C183). Heavy Uruguayan lambs had higher intramuscular fat content (5.92%) than German (4.25%) and British (4.32%) lambs, and this content was twofold higher than light lambs (Spanish (2.41%) and light Uruguayan (3.05%)). Heavy Uruguayan, German and British lambs had a low polyunsaturated/saturated (P/S) ratio due to their high saturated fatty acid (SFA) content and proportion. Principal component analysis was performed to study the relationship between fatty acids. Spanish lambs were clearly separated from the other types and were situated close to the proportions of short chain and n - 6 fatty acids and n - 6/n - 3 ratio in the data plot for fatty acid proportions. Light Uruguayan lambs were located close to long chain fatty acids, and heavy Uruguayan and British lambs were placed near the antithrombotic potential (ATT), stearic acid (C180), SFA and conjugated linoleic acid (CLA) proportions. German lambs were located between Spanish lambs and the other types. © 2005 Elsevier Ltd. All rights reserved

    Eating quality of beef, from different production systems, assessed by German, Spanish and British consumers

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    The acceptability of beef from Uruguay (UY), based on eating quality, was compared with beef produced in different European countries (Germany, DE, Spain, ES and United Kingdom, UK). Consumer tests were conducted in DE, ES and UK (each comprising 200 consumers) using 'Hall Tests'. In each country four samples were evaluated, two from Hereford steers from UY (finished at 2 and 3 years) and two from local meat (the same meat sample aged 7 or 20 d). Consumers evaluated tenderness, flavour and overall acceptability using 8-point category scales. Hierarchical cluster analysis, highlighted the existence of different clusters of consumers. Two main clusters were identified in DE and UK. The main cluster identified in DE, was labelled as Prefer foreign-imported beef (n = 128). These consumers preferred (P < 0.05) the samples from UY_2y in terms of tenderness and overall acceptability. The other cluster was labelled as Prefer local beef in terms of flavour and overall acceptability (P < 0.05) and comprised the majority of consumers from ES (n = 176) and UK (n = 153) and the cluster 2 from DE (n = 69). UK, cluster 2 (n = 33) that did not discriminate between origin and ageing time of beef. These results indicate that consumers did not prefer the same type of meat within the same country and it is possible that there are individual preferences that could lead to the concept of market segmentation being based on taste preferences. It would appear that Uruguayan beef would be very acceptable in Germany and to a lesser extent in Britain and Spain, although further studies are required that include labelling information. © 2006

    Estabilidade físico-química, microbiológica e sensorial de carne ovina embalada a vácuo estocada sob refrigeração Physical and chemical stability microbiological and sensory analysis of vacuum packed sheep meat stored under refrigeration

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    A carne ovina é comercializada atualmente em sua quase totalidade na forma congelada, porém com a tendência atual de maior procura por produtos de conveniência, vislumbra-se a necessidade de o mercado começar a ofertar esta carne na forma de cortes refrigerados. Este trabalho teve como objetivo avaliar a estabilidade e segurança de lombo de cordeiro embalado a vácuo quando estocado sob refrigeração. A estabilidade foi avaliada por meio de análises físicas e químicas (oxidação lipídica, cor objetiva, valor de pH, composição centesimal, perda de água por cocção e textura instrumental), microbiológicas (contagem total de psicrotróficos anaeróbios, coliformes termotolerantes a 45°C, estafilococos coagulase positiva e presença de Salmonella) e sensorial (cor, aparência geral e aroma). A carne ovina apresentou-se estável durante o período de 28 dias com relação à maioria dos índices físicos e químicos avaliados e dentro dos padrões estabelecidos pela legislação brasileira para micro-organismos patogênicos. Durante o armazenamento, detectou-se um aumento elevado das contagens de micro-organismos psicrotróficos anaeróbios, atingindo valores da ordem de 10(7)UFC g-1 amostra já aos 14 dias, porém os consumidores não detectaram alterações sensoriais significativas durante todo o período. Conclui-se que a vida útil de lombo ovino armazenado a 4°C é de no mínimo 28 dias.<br>Lamb is commercialized today almost entirely in frozen form, but, considering the current trend to greater demand for convenience products, it becomes more evident the need of availability of chilled cuts of meat in the market. The objective of this study was to evaluate the stability and safety of lamb meat packed under vacuum when stored under refrigeration. The lamb meat samples were packed in high barrier multilayer plastic films and stored under refrigeration (4±1°C). The stability was evaluated by means of physical and chemical analysis (lipid oxidation, objective color, pH value, chemical composition, cooking losses and instrumental texture), microbiological analysis (total count of psychrotrophic anaerobic, coliform count at 45°C, coagulase-positive staphylococci and the presence of Salmonella) and sensory analysis (color, flavor and overall appearance). The vacuum packed lamb meat remained stable as to most physical and chemical indexes and microbiological indexes showed good stability throughout the 28 days of storage according to Brazilian legislation standards to pathogenic microorganisms. In relation to the stability evaluation of chilled sheep loin, it was detected a high increase of counts for psychrotrophic anaerobic microorganisms, reaching around 10(7)CFU g-1 sample at 14 days storage, but the pannelists did not detect significant sensory changes during all the period. It is concluded that the shelf life of sheep loin stored at 4°C, is at least, 28 days
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