Perfil de lipídios, composição de ácidos graxos e teor de colesterol em camarões

O presente trabalho foi realizado com objetivo de comparar o efeito do ambiente sobre a concentração de lipídeos, a composição de ácidos graxos e o conteúdo de colesterol nas duas espécies de camarões cultivadas em diferentes salinidades de água. Foram utilizados neste estudo os camarões Litopenaeus vannamei, uma espécie cultivada em água doce e o Farfantepenaeus schimitti, criado em água salgada. O conteúdo de lipídeos de camarão de água doce foi cerca de 1,32% contra 0.97% de água salgada. A carne de camarão (Litopenaeus vannamei) de água doce se mostrou nutricionalmente mais sadia que a do camarão (Farfantepenaeus schimitti) de água salgada em relação à composição de ácidos graxos e concentração de colesterol. Treze e onze ácidos graxos foram detectados em óleos extraídos do Litopenaeus vannamei e Farfantepenaeus schimitti, respectivamente. A concentração total de ácidos graxos saturados em camarão de água salgada foi maior que no camarão de água doce, enquanto, este apresentou maior percentagem de ácidos graxos mono-insaturados e poli-insaturados. Uma diferença significativa nos ácidos graxos poli-insaturados entre as duas espécies foi observada. Em relação ao colesterol, o camarão de água doce apresentou uma concentração de 62.3 mg/100 g, enquanto o camarão de água salgada 271.3 mg/100 g de filé.

Aceite de almendra de la semilla de Sterculia striata: Caracterización y estabilidad térmica

The objective of the present work was to characterize sterculia seed kernel oil. The chemical composition of the seeds, physicochemical properties as well as the fatty acid composition of the kernel oil was determined. The chemical composition of kernel flour presented about 25.8% lipid content. The physicochemical parameters such as acid, iodine, peroxide and saponification values were 0.82 (% as oleic acid), 69.2 (g iodine/100 g oil), 4.20 (m eq./kg) and 136.1 (mg. KOH/g oil), respectively. With respect to fatty acid composition, the oil contained 36.2, 43.7 and 10.9% saturated, monounsaturated and polyunsaturated fatty acids, respectively. Palmitic acid (31.9%), oleic acid (41.7%) and linoleic acid (10.73%) were the principal saturated, monounsaturated and polyunsaturated fatty acids. Two cyclopropanoid fatty acids i.e. sterculic and malvalic acid were identified at a concentration of 5.3 and 2.3%, respectively. With regards to the thermal stability of the oil, a thermogravimetric analysis (TGA) has shown that the oil was stable until about 284 °C, above that the oil started loosing mass, while a differential thermogravimetric analysis (DTGA) revealed three stages of degradation with an increase in temperature. These stages corresponded to the degradation of polyunsaturated, monounsaturated and saturated fatty aids. The Differential Scanning Calorimetric (DSC) analysis showed the existence of two exothermic events of energy transition, one of which is related to the oxidation reactions and another to the decomposition of the oil. Exothermic transitions in the oil were initiated at a temperature (Ti) of 287.79 °C, and terminated at 347.81 °C, with an enthalpy variation of 11.69 joules.g–1 and at initial temperature (Ti) of 384.87 °C, peak temperature (Tp) 415.71 °C, final temperature (Tf) 448.9 °C and an enthalpy of 200.83 Joules. G–1El objetivo de este trabajo fue la caracterización del aceite de almendra de la semilla de Sterculia striata. Se determinaron la composición química, las propiedades químico-físicas, composición en ácidos grasos, así como la estabilidad térmica de la harina (polvo) de almendra. La composición química de la harina contiene cerca de 25,8% de lípidos, los parámetros químico-físicos, tales como: índice de acidez, yodo, peróxido y saponificación fueron 0,82% (ácido oleico), 69,2 (g yodo/100 g de aceite), 4,20 m.eq./kg de aceite y 136,1 (mg KOH/g de aceite), respectivamente. Con relación a la composición en ácidos grasos, el aceite contiene 36,2; 43,7 y 10,9% de ácidos grasos saturados, monoinsaturados y polyinsaturados, respectivamente. El ácido palmítico (31,9%), oleico (41,7) y linoleico (10,73%), fueron los principales ácidos grasos saturados, monoinsaturados y polyinsaturados, respectivamente. Los ácidos grasos ciclopropenoides, esto es, ácidos estercúlico y malválico fueron identificados y cuantificados en la proporción de 5,3 y 2,3%, respectivamente. Con respecto a la estabilidad térmica del aceite, el análisis termogravimétrico (TGA) demostró que el aceite es estable hasta la temperatura de 284 °C, a partir de este valor el aceite comenzó a perder masa. El análisis termogravimétrico diferencial (DTGA) indicó la existencia de tres etapas de degradación con el aumento de la temperatura del aceite. Estas etapas significan la degradación de los aceites saturados, monoinsaturados y polyinsaturados. El análisis mediante calorimetría diferencial de barriido (DSC) detectó dos zonas de transición de energía exotérmica, una debida a la reacción de oxidación y la otra a la descomposición de los ácidos grasos. La primera transición exotérmica del aceite comenzó a la temperatura (Ti) de 287,79 °C con una variación de entalpía de 11,69 J/g y, la segunda con la temperatura inicial (Ti) de 384,87 °C, una temperatura de pico (Tp) 415,71 °C y una temperatura final (Tf) de 448,9 °C con una variación de entalpía de 200,83 J/g

Flour production from shrimp by‑products and sensory evaluation of flour‑based products

O objetivo deste trabalho foi avaliar a  produção de um tipo de farinha de subprodutos (cefalotórax), obtidos da indústria de beneficiamento do camarão (Litopenaeus vannamei), e realizar uma análise sensorial de produtos formulados com a farinha. Foram feitas análises físico‑químicas e microbiológicas do cefalotórax fresco e da farinha formulada, assim como a determinação do teor de colesterol dessa farinha e a avaliação sensorial de uma sopa e um pastel feitos com ela. Pelas análises microbiológicas, nenhum microrganismo patogênico foi encontrado nas amostras. As análises físico‑químicas da farinha mostraram elevados teores de proteínas (50,05%) e minerais (20,97%). A farinha de cefalotórax de camarão apresentou elevado teor de colesterol. A avaliação sensorial indicou boa aceitação dos produtos, com índice de aceitabilidade satisfatório (81% para a sopa e 83% para o pastel), o que indica que o cefalotórax de camarão, na forma de farinha, tem potencial para o desenvolvimento de novos produtos.The objective of this work was to evaluate the production of flour using by‑products (cephalothorax) obtained from the shrimp (Litopenaeus vannamei) industry, and to perform a sensory analysis of shrimp flour‑based products. Physicochemical and microbiological analyses on fresh cephalothorax and on manufactured flour were performed, as well as the determination of cholesterol content of this flour, and the sensorial evaluation of soup and pastry made with this flour. By the microbiological analyses, no pathogenic microorganism was detected in the samples. Physicochemical analyses of flour showed high levels of protein (50.05%) and minerals (20.97%). Shrimp cephalothorax flour showed high levels of cholesterol. The sensory evaluation indicated a good acceptance of the products, with satisfactory acceptability index (81% for soup, and 83% for pastry), which indicates that shrimp cephalothorax in the form of flour has a potential for developing new products

Mapping density, diversity and species-richness of the Amazon tree flora

Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Author correction: One sixth of Amazonian tree diversity is dependent on river floodplains

In the version of the article initially published, the affiliation of Edgardo Manuel Latrubesse was incorrect and has now been amended to Environmental Sciences Graduate Program-CIAMB, Federal University of Goiás, Goiânia, Brazil in the HTML and PDF versions of the article

Mapping density, diversity and species-richness of the Amazon tree flora

Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost