Effect of packaging, muscle and storage on beef physicochemical stability

Estudou-se a efetividade de filmes plásticos incorporados com absorvedor de luz ultravioleta (UV) sobre a estabilidade da cor e indicadores físico-químicos desta estabilidade, nos cortes de músculos bovinos Psoas major (PM) e regiões interior (IST) e superficial (OST) do Semitendinosus (ST). Também foi avaliada a contribuição dos indicadores físico-químicos sobre a estabilidade da cor. Filmes plásticos, controle e com absorvedor UV adicionado, foram desenvolvidos e analisados quanto às suas propriedades mecânicas assim como de permeabilidade ao oxigênio e transmissão de luz. A incorporação do absorvedor UV à resina de polietileno reduziu a transmissão de luz UV do filme plástico de 61% para 12%, e não afetou (P > 0,05) a sua permeabilidade ao oxigênio e propriedades mecânicas. A incorporação de absorvedor UV ao filme de polietileno não produziu alterações (P > 0,05) nas propriedades indicativas de estabilidade de cor analisadas nos diversos cortes musculares. Durante o período de estocagem, foi observado, para todos os cortes de músculos, aumento nos percentuais de metamioglobina (MMb), taxa de oxidação lipídica (TBARs) e pH. Foi também observada uma redução nos índices de vermelho (a*), percentuais de MbO2, índice de amarelo (b*), taxa de consumo de oxigênio (TCO) e na atividade de metamioglobina redutase (MRA). À exceção do OST, que se tornou levemente mais claro (P 0,05) com o tempo. O potencial de óxidoredução (Eh) apresentou variação (P 0,05). O PM apresentou (P 0,05) diferença no Eh entre os músculos. Os resultados sugerem que o filme UV desenvolvido, apesar de promover bom bloqueio de luz UV, não foi efetivo para prolongar a vida de prateleira da carne, por, provavelmente, não eliminar, por completo, a transmissão de luz UV emitida pela lâmpada fluorescente. Por sua vez, parece razoável concluir que cortes de músculos em que os processos que induzem à oxidação dos pigmentos da carne, como elevadas TCO e taxa de oxidação lipídica são muito superiores à capacidade redutora (MRA), como no PM, o acúmulo de metamioglobina é muito rápido, tendo o músculo uma baixa estabilidade de cor. Por outro lado, cortes musculares, tais como o IST, em que a ação redutora (alta MRA) parece ser suficiente para compensar o estresse oxidativo imposto pela TCO e TBARs, ou, cortes musculares, como o OST, em que os processos oxidativos não são pronunciados, o acúmulo de metamioglobina é retardado, tendo a carne maior estabilidade de cor.Effectiveness of plastic films incorporated with UV light absorber on color stability, and it s physical-chemical indicators, of beef Psoas major (PM), Semitendinosus inner region (IST) and Semitendinosus outer region (OST) were evaluated. The contribution of the physical-chemical indicators to beef color stability was also evaluated. Plastic films, control and with added UV absorber, were developed and analyzed for their mechanical properties as well as oxygen and light transmission permeability. Incorporation of UV absorber to the polyethylene resin reduced plastic film UV light transmisson from 61% to 12% and did not (P > 0.05) affect its oxygen permeability and mechanical properties. Film incorporation with UV absorber did not affect (P > 0.05) any of the analyzed properties indicative of color stability. For all muscles it was observed, during the storage period, an increase in metmyoglobin (MMb) level, lipid oxidation rate (TBARs) and pH. It was also observed a reduction of redness (a*), oxymyoglobin (MbO2) levels, yellowness (b*), oxygen consumption rate (OCR) and metmyoglobin reductase activity (MRA). Except for the OST muscle, which became lighter (P 0.05) during storage. Oxidation reduction potential (ORP) varied (P 0.05). PM muscle presented (P 0.05). Results suggests that despite the relative light blocking action of the UV absorber, its incorporation into the plastic film was not effective in extending beef shelf life probably by not completely eliminating absorption of the UV light generated by the fluorescent lamp. In addition, it seems reasonable to conclude that muscles in which the processes inducing meat pigment oxidation such as high OCR and lipid oxidation rate are superior to their reducing capacity (MRA), such as the PM muscle, accumulation of MMb is very fast making it of low color stability. On the other hand muscles, such as the IST, having sufficient reducing action (high MRA) to compensate the oxidative stress imposed by OCR and lipid oxidation, or muscles, such as the OST, were oxidative processes are not pronounced, MMb accumulation is retarded leading to a greater color stability.Conselho Nacional de Desenvolvimento Científico e Tecnológic

Fatty acid composition in muscles from lambs fed diets containing agroindustrial co-products

ABSTRACT The objective of this study was to evaluate the effects of supplementing diet of lambs with agroindustrial co-products on the nutritional quality of meat fat and study the variation of fat quality parameters based on the type of muscle. Twenty lambs were distributed into four experimental groups and fed a control diet or diets containing cottonseed, sunflower meal, and castor cake. After 106 experimental days, the animals were slaughtered. Samples of Biceps femoris, Longissimus dorsi, Semimembranosus, and Triceps brachii muscles were taken for fatty acid and cholesterol analyses. Castor cake and sunflower meal diets produced meats with lower levels of n-6 polyunsaturated fatty acids (PUFA) compared with the control diet. Castor cake diet contributed to tissue reduction of n-3 PUFA. Lower conjugated linoleic acid concentration and polyunsaturated:saturated fatty acid (P:S) ratio and higher saturated fatty acids content and Thrombogenicity Index were observed in Longissimus dorsi meat. Of the co-products studied, although castor cake diet reduced cholesterol levels in Biceps femoris muscle, sunflower meal was identified as the preferred choice for lamb feeding, since it reduced n-6 PUFA without, however, decreasing n-3 PUFA. Longissimus dorsi meat had the lowest fat quality indexes. The more oxidative muscles, such as Biceps femoris, tend to generate meats with higher cholesterol concentrations

Influência de Rumensin®, óleo de soja e níveis de concentrado sobre o consumo e os parâmetros fermentativos ruminais em bovinos Effect of Rumensin®, soybean oil and concentrate levels on ruminal parameters and dry matter intake in bovines

Objetivou-se avaliar os efeitos de óleo de soja (500 mL/animal/dia), Rumensin® (3 g/animal/dia) e níveis de concentrado (0, 25, 50, 75%) na dieta de bovinos, e cana-de-açúcar como volumoso, sobre alguns parâmetros ruminais e consumo de matéria seca. Foram utilizados quatro bovinos 7/8 holandês-zebu fistulados no rúmen, com peso vivo médio de 400 kg. O experimento consistiu de quatro períodos de 15 dias, sendo 12 dias para adaptação à dieta e três dias para coletas de amostras. Utilizou-se um nível de concentrado em cada período e o óleo e rumensin foram distribuídos em quadrado latino, em um fatorial 2x2. As análises de amônia, pH e AGV do líquido ruminal foram feitas em amostras coletadas através da fístula às 0, 3 e 6 horas após a alimentação. A leitura do pH foi feita com potenciômetro, as análises de amônia por colorimetria e as de ácidos graxos voláteis por cromatografia gasosa. O acetato, a relação acetato:propionato e o pH decresceram, e os teores de isobutirato, isovalerato e amônia ruminal aumentaram com a elevação do nível de concentrado. O propionato aumentou e a relação acetato:propionato diminuiu com a presença de Rumensin. O butirato aumentou com o óleo quando a dieta continha somente volumoso e diminuiu com o aumento de concentrado. O pH e a amônia ruminais diminuíram com o tempo de coleta. A atividade in vitro de desaminação pela população microbiana decresceu com o aumento do nível de concentrado e aumentou na presença de óleo. O consumo de matéria seca aumentou com a elevação do nível de concentrado e diminuiu na presença de Rumensin e óleo. Todos os outros efeitos principais e interações não foram significativos.<br>The objective of this research was to evaluate the effects of soybean oil (500 mL/animal/day), Rumensin® (3g/animal/day) and levels of concentrate (0, 25, 50 and 75%) in the diet of bovines, and sugarcane as a forage source, in some ruminal parameters and dry matter intake. There were used four rumen fistulated 7/8 holstein-zebu steers, at 400 kg of live weight. The experiment consisted of four periods of 15 days, in which 12 were for adaptation to the diets and three for sampling. It was used one level of concentrate in each period and oil and Rumensin were distributed in a latin square, as 2x2 factorial design. Ammonia, pH and VFA analysis in the rumen fluid were measured in samples collected at 0, 3 and 6 hours after feeding. The pH was immediately measured by glass electrode, ammonia was analysed by colorimetry and VFA by gas chromatography. Acetate, acetate to propionate ratio and pH were decreased, but isobutyrate, isovalerate, and ruminal ammonia were increased in high concentrate levels. Propionate was increased and acetate to propionate ratio was decreased with Rumensin. Butyrate was increased with oil in the forage diet, but decreased with increasing concentrate. Ruminal ammonia and pH were decreased during sampling time. In vitro deamination activity by the mixed ruminal bacteria decreased by increasing concentrate and increased by adding oil. Dry matter intake increased by increasing concentrate level and decreased with Rumensin and oil. All other main effects and interactions were not significant

Seminário de Dissertação (2024)

Página da disciplina de Seminário de Dissertação (MPPP, UFPE, 2022) Lista de participantes == https://docs.google.com/spreadsheets/d/1mrULe1y04yPxHUBaF50jhaM1OY8QYJ3zva4N4yvm198/edit#gid=

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora

Growing knowledge: an overview of Seed Plant diversity in Brazil

Abstract An updated inventory of Brazilian seed plants is presented and offers important insights into the country's biodiversity. This work started in 2010, with the publication of the Plants and Fungi Catalogue, and has been updated since by more than 430 specialists working online. Brazil is home to 32,086 native Angiosperms and 23 native Gymnosperms, showing an increase of 3% in its species richness in relation to 2010. The Amazon Rainforest is the richest Brazilian biome for Gymnosperms, while the Atlantic Rainforest is the richest one for Angiosperms. There was a considerable increment in the number of species and endemism rates for biomes, except for the Amazon that showed a decrease of 2.5% of recorded endemics. However, well over half of Brazillian seed plant species (57.4%) is endemic to this territory. The proportion of life-forms varies among different biomes: trees are more expressive in the Amazon and Atlantic Rainforest biomes while herbs predominate in the Pampa, and lianas are more expressive in the Amazon, Atlantic Rainforest, and Pantanal. This compilation serves not only to quantify Brazilian biodiversity, but also to highlight areas where there information is lacking and to provide a framework for the challenge faced in conserving Brazil's unique and diverse flora