Green tea as a promising extract of active food packaging

Introduction: Tea is one of the most popular and frequently consumed beverages in the world and its consumption dates back to more than 2000 years in China and then spread to other areas including Japan and later on to Europe (Zhao et al., 2014). Green tea is produced from Camellia sinensis (L.) Kuntze leaf infusion and is well known for its pleasant flavour and is associated with positive health effects. The biological activity of green tea is related with the considerable amount of catechins and other phenolic compounds, in particular flavonols and phenolic acids, present in its composition (Zhao et al., 2014). These phenolic compounds prevent the oxidative damage through their antioxidant activity and also reduce the risk of cancer, cardiovascular and neurodegenerative diseases (Lorenzo et al., 2014). The process of oxidation is one of the most common mechanisms of degradation of foodstuffs and it can alter food texture and colour, decrease nutritional quality, develop off-odours and also produce possible toxic compounds. As a consequence, the shelf-life and commercial acceptability of the food products decrease. Currently, one of the major concerns of the consumers is the impact of food on health. In line with this, food industry is trying to substitute synthetic additives by natural compounds. These can be directly added to food or incorporated in food packaging with the aim of being controlled released throughout the product shelf life. This concept is so-called Active packaging and allows the packaging to positively interact with foods to increase food shelf-life. This interaction can be due to the intended release of compounds from packaging to the foods or to their headspace, or due to the scavenging of compounds by the packaging from the packaged foods. Due to the antioxidant capacity of green tea, its extract can be proposed as an alternative to synthetic antioxidants (Giménez et al., 2013). In fact, it has already been applied in active food packaging. Material and Methods: The present review focuses on the application of green tea extract in active packaging. In this regard, an extensive bibliographic research was carried out in order to evaluate the polymers already used to incorporate green tea extract, as well as the mechanical and barrier properties and efficiency of these packaging systems in contact with foods. Results and Discussion: The chemical composition of tea leaves on active compounds with antioxidant activity is well documented. Bioactive constituents of the tea leaves include catechin gallates such as epigallocatechin gallate and gallocatechin gallate (López de Dicastillo et al., 2011). However the levels of these compounds depend on many factors, such as the edaphoclimatic conditions and drying conditions of the Camellia sinensis leaves. Moreover the extraction and analysis methods can also have a great influence in their content. Green tea extract has already been incorporated into different polymers. In fact, most of them are edible such as proteic films from distilled dry beans (Yang et al., 2016), agar (Lacey et al., 2014), chitosan (Siripatrawan et al., 2012; Siripatrawan et al., 2010) and gelatine (Hong et al (2009). Green tea extract (GTE) can offers protection against oxidation, significantly reducing rancidity and thereby extending the shelf-life of packaged foods. Moreover the sensory analysis also demonstrated that packaged food was unaffected by GTE (Carrizo et al., 2016). According to Yang et al. (2016), the incorporation of the GTE did not alter the physical properties of the films. According to Siripatrawan et al. (2010), the incorporation of GTE improved the mechanical and water vapour barrier properties. In general, GTE provides a very positive impact in the reduction of oxidation of all types of food, from aqueous to fatty (López de Dicastillo et al., 2011), although most of the studies selected meat (e.g. pork, pork sausages, pork loins), or fish products (e.g. fillets of hake, salted sardines) to test the efficiency of the active films. Conclusion: Green tea has great potential of application in active food packaging due to its antioxidant capacity. Therefore, in the near future, is it possible that new food packaging based on GTE will arise in the market. However, more studies are require to elucidate about the concentrations of GTE that do not affect or affect positively the mechanical or barrier properties of the packaging and that are effective as oxidation inhibitors of packaged foodsThis work was supported by the research project “Development of methodologies for the evaluation of polymeric food packaging components and determination of their structural and mechanical properties” (2016DAN 1289) funded by the National Institute of Health Dr Ricardo Jorge, I.P., Lisbon, Portugal.N/

Filme ativo com extrato de chá verde: eficácia contra a oxidação lipídica

As embalagens ativas têm como objetivo proteger e prolongar a vida útil dos alimentos, aumentando a sua qualidade, segurança e integridade. Na industria alimentar, este conceito de embalagem ativa foi aplicado como forma de controlar o fenomeno da oxidacao lipidica em alimentos com alto teor de gordura, sendo que esta e uma das principais causas de perda de qualidade destes alimentos. A composição química do chá verde tem revelado um grande interesse no que diz respeito a prevenção da oxidação lipídica. Na sua constituição, as folhas de chá verde possuem um teor elevado de compostos fenólicos, que tem sido associados a sua atividade antioxidante. Devido às suas propriedades, o chá verde e considerado um ótimo agente antioxidante natural. O poli (acido láctico) ou ácido poliláctico (PLA) e um polímero alifático cujo monómero e derivado de recursos renováveis, como amido de milho, raízes de tapioca e cana de açúcar. O polímero e formado através da fermentação de amido e condensação de ácido láctico. No presente estudo, fatias de salmão fumado foram embaladas com um filme de PLA, com extrato de chá verde incorporado em diferentes concentrações, 1% e 2%, e, posteriormente, armazenadas durante 7, 15, 30, 45 e 60 dias, em refrigeração. Um filme de PLA sem o extrato de chá verde foi usado como controlo. Para avaliar a eficácia do filme ativo contra a oxidação lipídica, utilizou-se o teste de Substancias Reativas ao Ácido Tiobarbiturico (TBARS). Este ensaio mede o conteudo de malonaldeido (MDA) que e formado durante a oxidação lipídica pela decomposição dos ácidos gordos polinsaturados em hidroperoxidos. Os resultados foram expressos em mg de MDA por kg de salmão fumado. Os resultados mostraram que as fatias de salmão fumado embaladas com o filme de PLA/chá verde apresentaram menor teor de MDA do que aquelas embaladas com o filme controlo. As fatias de salmão fumado embaladas com o PLA/chá verde2% apresentaram menor quantidade de MDA em todos os momentos de contacto, exceto apos 15 dias, onde se verificou menor teor de MDA nas fatias de salmão embaladas com o filme ativo com 1% de extrato de chá verde. Estes resultados mostraram que a incorporação do extrato de chá verde no PLA protege o salmão fumado da oxidação lipídica. Contudo, devem ser realizados estudos adicionais para confirmar a inibição da oxidação lipídica, como o índice de peróxido, o valor de p-anisidina e a determinação do hexanal.Este trabalho foi financiado pelo projeto de investigação “Development of methodologies for the evaluation of polymeric food packaging components and determination of their structural and mechanical properties (2016DAN 1289)” financiado pelo Instituto Nacional de Saúde Doutor Ricardo Jorge (INSA, I.P.). Mariana Andrade agradece a bolsa de investigação (2016/iFILM/BM) no âmbito do projeto iFILM.N/

Idosos institucionalizados no concelho de Viseu: Hábitos alimentares

O envelhecimento da população, bem como a alteração da dinâmica da família, têm contribuído diretamente para o aumento do número de idosos institucionalizados. A incidência da desnutrição alcança níveis elevados nestes idosos, sendo essencial o seu diagnóstico precoce para a melhoria da sua qualidade de vida. Constitui objetivo primordial do estudo a avaliação do estado nutricional de idosos institucionalizados no concelho de Viseu, Portugal. A amostra (n=120) é constituída por idosos de ambos os sexos, institucionalizados, com idade igual ou superior a 65 anos, com capacidade para se colocar de pé, sem demência e que não sejam portadores de patologia passível de afetar a digestão, absorção ou utilização dos nutrientes. A avaliação do estado nutricional é determinada tendo em conta parâmetros antropométricos e dietéticos, através da avaliação da ingestão alimentar (registo de 3 dias) e Mini Nutricional Assessment (MNA). Os questionários aplicados estão validados para a população portuguesa idosa e foram aplicados após consentimento informado. Considerou-se um nível de confiança de 95%. A amostra estudada é maioritariamente feminina (70,0%), com uma idade média de 82,4±6,4 anos. A determinação do IMC mostrou que 12,5% dos idosos avaliados têm baixo peso (IMC 17,7±1,3); 46,7% são eutróficos (IMC 19,9±0,5); 11,7% apresentam excesso de peso (IMC 22,1±0,7), sendo 29,1% classificados como obesos (IMC 28,8±4,2). O MNA mostra que 65% dos idosos apresenta estado nutricional normal, estando sob risco de desnutrição 33,3%, verificando-se, este risco de desnutrição ser superior nos idosos ≥ 75 anos e na população feminina (3:1). A ingestão energética média por dia é significativamente inferior à recomendada (p≤0,05), sendo a ingesta de proteína e hidratos de carbono superior aos valores recomendados para a população (p≤0,05). O consumo lipídico é maioritariamente normolipídico (54,1%), devendo-se a um consumo reduzido de ácidos gordos monosaturados vs. polinsaturados.info:eu-repo/semantics/publishedVersio

NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

Xenarthrans – anteaters, sloths, and armadillos – have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with 24 domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, ten anteaters, and six sloths. Our dataset includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data-paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the south of the USA, Mexico, and Caribbean countries at the northern portion of the Neotropics, to its austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n=5,941), and Cyclopes sp. has the fewest (n=240). The armadillo species with the most data is Dasypus novemcinctus (n=11,588), and the least recorded for Calyptophractus retusus (n=33). With regards to sloth species, Bradypus variegatus has the most records (n=962), and Bradypus pygmaeus has the fewest (n=12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other datasets of Neotropical Series which will become available very soon (i.e. Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans dataset

ATLANTIC-CAMTRAPS: a dataset of medium and large terrestrial mammal communities in the Atlantic Forest of South America

Our understanding of mammal ecology has always been hindered by the difficulties of observing species in closed tropical forests. Camera trapping has become a major advance for monitoring terrestrial mammals in biodiversity rich ecosystems. Here we compiled one of the largest datasets of inventories of terrestrial mammal communities for the Neotropical region based on camera trapping studies. The dataset comprises 170 surveys of medium to large terrestrial mammals using camera traps conducted in 144 areas by 74 studies, covering six vegetation types of tropical and subtropical Atlantic Forest of South America (Brazil and Argentina), and present data on species composition and richness. The complete dataset comprises 53,438 independent records of 83 species of mammals, includes 10 species of marsupials, 15 rodents, 20 carnivores, eight ungulates and six armadillos. Species richness averaged 13 species (±6.07 SD) per site. Only six species occurred in more than 50% of the sites: the domestic dog Canis familiaris, crab-eating fox Cerdocyon thous, tayra Eira barbara, south American coati Nasua nasua, crab-eating raccoon Procyon cancrivorus and the nine-banded armadillo Dasypus novemcinctus. The information contained in this dataset can be used to understand macroecological patterns of biodiversity, community, and population structure, but also to evaluate the ecological consequences of fragmentation, defaunation, and trophic interactions. © 2017 by the Ecological Society of Americ