Otimizando o uso de sorbato de potássio e metabissufito de sódio para a estabilidade química e microbiológica de água de coco carbonatada

Coconut water is popular worldwide, mainly because of its pleasant sensory characteristics, nutritional value and low calorie density. However, coconut water is a highly perishable product due to the presence of enzymes such as peroxidase and polyphenoloxidase, which cause undesirable changes in colour, and also because of its susceptibility to microbial spoilage. The use of chemical additives has been adopted by the industry with the intent of increasing product shelf life. In this study, the efficiency of the preservatives potassium sorbate and sodium metabisulphite was assessed using a Central Composite Rotational Design (CCRD) to determine the stability of carbonated coconut water, varying the concentrations of potassium sorbate from 0 to 500 mg.L-1, and of sodium metabisulphite from 0 to 100 mg.L-1. The chemical evaluations included carbonation volume, pH, soluble solids, dissolved oxygen and carbon dioxide, acidity, ascorbic acid, polyphenoloxidase and peroxidase activities, colour and turbidity attributes. The microbiological evaluations considered the total aerobic plate count and the enumeration of yeasts and moulds. It was observed that concentrations of 375 mg.L-1 of potassium sorbate and 75 mg.L-1 of sodium metabisulphite gave the best quality attributes with respect to minor changes in acidity and colour of the coconut water, providing that the raw material had low microbiological contamination.A água de coco é muito popular em todo o mundo, principalmente em virtude das suas características sensoriais agradáveis, do valor nutricional e das baixas calorias. No entanto, a água de coco é um produto altamente perecível em função da presença de enzimas - tais como peroxidase e polifenoloxidase, que causam alterações indesejáveis na cor - e também em função da sua susceptibilidade à deterioração microbiana. O uso de aditivos químicos tem sido adotado pela indústria com a intenção de aumentar a vida de prateleira do produto. Neste estudo, a eficiência dos conservantes sorbato de potássio e metabissulfito de sódio foi avaliada considerando-se a estabilidade da água de coco carbonatada por meio do delineamento composto central rotacional (DCCR), variando as concentrações de sorbato de potássio entre 0 e 500 mg.L-1, e de metabissulfito de sódio entre 0 e 100 mg.L-1. Foram realizadas avaliações físico-químicas de volume de carbonatação, pH, sólidos solúveis totais, oxigênio e dióxido de carbono dissolvidos, acidez, ácido ascórbico, atividade de polifenoloxidase e peroxidase, cor e atributos de turbidez. As análises microbiológicas realizadas foram de contagem total de aeróbios, bem como de enumeração de bolores e leveduras. Observou-se que as concentrações de 375 mg.L-1 de sorbato de potássio e 75 mg.L-1 de metabissulfito de sódio apresentaram os melhores atributos de qualidade, no que diz respeito a pequenas alterações na acidez e à cor da água de coco, desde que a matéria-prima apresentasse contaminação microbiológica baixa.12513

INOVAÇÕES SOBRE SISTEMAS DE EMBALAGENS PARA ALIMENTOS PROCESSADOS TERMICAMENTE

Esta revisão de literatura teve como objetivo avaliar os diferentes sistemas de embalagem disponíveis para alimentos termicamente processados e como as embalagens afetam o tipo de processo utilizado e a qualidade final do produto obtido. Foram abordados os principais processos térmicos utilizados e os seus requerimentos em termos de resistência (mecânica e térmica) da embalagem, além das vantagens e limitações dos principais materiais utilizados. Também foram tratados os desenvolvimentos recentes e importantes para superar parcialmente as limitações de cada tipo de material e reduzir os custos envolvidos, além das propriedades de barreira exigidas para que o alimento não sofra alterações, especialmente de ordem físico-química por oxidação, umidade e migração de materiais da embalagem, durante o seu armazenamento. Concluiu-se que existem várias opções de embalagens para alimentos termicamente tratados e que, enquanto embalagens tradicionais passam por constantes pesquisas para se manterem competitivas, as de plástico ou flexíveis são muito estudadas visando o desenvolvimento de sistemas compatíveis com o processamento térmico e baixo custo

Pratos e mais pratos: louças domésticas, divisões culturais e limites sociais no Rio de Janeiro, século XIX

Reply to ten comments on a paper published in the last issue of this journal. The discussion follows along six main lines: History museums, identity, ideology and the category of nation; the need of material collections and their modalities: patrimonial, operational, virtual; theater versus laboratory; visitors and their ambiguities; Public History: the museum and the academy.Resposta aos comentários de dez especialistas que contribuíram no debate de texto publicado no último número desta revista. A discussão orientou-se segundo seis tópicos principais: museus históricos, identidade, ideologia e a categoria de nação; a necessidade de acervos materiais e suas modalidades: acervo patrimonial, operacional, virtual; teatro versus laboratório; o público e suas ambigüidades; História Pública: o museu e a Academia

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

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

ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ

Influência da temperatura e do ácido ascórbico sobre a estabilidade físico-química e atividade enzimática da água de coco (Cocos nucifera L.) acondicionada assepticament

Este estudo teve por objetivo avaliar a estabilidade físico-química da água de coco quando processada termicamente entre 138 e 144 °C por 10 segundos, com adição de ácido ascórbico nas concentrações de 0, 100 e 200 mg.L-1. Foram processados cinco lotes de água de coco em pequena escala, fazendo-se a avaliação de sua estabilidade por três meses. O tratamento térmico a 139 °C/10 segundos e o uso de 200 mg.L-1 de ácido ascórbico foram consideradas as melhores condições de processo para manter a estabilidade físico-química da água de coco esterilizada e acondicionada assepticamente

Processamento e avaliação de estabilidade de bebida isotônica em garrafa plástica Processing and stability evaluation of isotonic drink in plastic bottle

Processou-se uma mistura isotônica com pH 3,4; objetivando-se a produção de uma bebida microbiologicamente estável, prescindindo de refrigeração. A bebida isotônica foi pasteurizada a 85&deg;C/5s em trocador de calor a placas e acondicionada em garrafas de polietileno tereftalato (PET) sanificadas por aspersão com solução de ácido peracético 0,3% durante 5s, a 30&deg;C. Foram processados 1 lote com 50mg/L de sorbato de potássio, 1 lote com 100mg/L e 1 lote sem sorbato. Os 3 lotes foram mantidos a 25&deg;C durante 26 semanas, sendo realizadas determinações de pH, sólidos solúveis, acidez total titulável, ácido ascórbico, testes de aceitação sensorial e contagens de microrganismos mesófilos aeróbios totais, bolores e leveduras durante a estocagem. Verificou-se diferença significativa (p<0,05) entre as médias das determinações de ácido ascórbico, no início e fim do período de estocagem, para os três lotes processados. As contagens de bolores e leveduras e mesófilos aeróbios totais foram <10 UFC/mL e <5,7 UFC/mL, respectivamente, para os três lotes analisados durante as 26 semanas. As médias das notas atribuídas nos testes de aceitação sensorial não diferiram entre si (p<0,05) ao longo da estocagem. Os resultados obtidos evidenciaram a possibilidade de produção de uma bebida isotônica em garrafa de PET sem adição de conservadores químicos; visto que, o lote processado sem sorbato apresentou resultados microbiológicos confiáveis, aliados a sua satisfatória aceitação sensorial e estabilidade físico-química.<br>The objective of this work was to obtain an isotonic drink by using pasteurization and packing into aseptic bottles, stable at room temperature, without the addition of chemical preservatives. For the sanitation of the plastic bottles some sanitizers were tested, based on their efficiency to destroy microorganism, maintaining minimum residual hydrogen peroxide, and keeping the drink sensory quality. The isotonic drink (pH 3,40) was thermaly processed in a plate pasteurizer at 85ºC/5s and packed into PET bottles sanitized by spraying peracetic acid at 0.3%/5s at 30ºC. The processed drink contained three different concentrations of potassium sorbate (control, 50 and 100mg/L). The stability of the products were evaluated at 25ºC for 26 weeks by measuring the pH, soluble solids, titrable acidity, ascorbic acid, microbial count, and sensory tests. The sensory evaluation and the count of the total mesophilic aerobic bacteria, moulds and yeast were measured during storage. There was no difference (p<0,05) for the pH, soluble solids and acidity of the processed drinks during the storage period except for the ascorbic acid which reduced to about 30% of the initial value. At 26 weeks the total bacteria and mould and yeast count were <5.7CFU/mL and <10CFU/mL, respectively. There was no sensory evaluation diference (p<0,05) during the storage test. Such results indicated that the formulated isotonic drink can be processed at the above conditions, without the addition of chemical preservatives, and stored at room temperature for at least 6 months in good commercial quality