Abstract This work aimed to characterize some of the bioactive compounds of Eugenia punicifolia (Kunth) DC. fruit to enhance the knowledge of its functional potential. Ripe fruits were collected from the restinga of Maricá, in the state of Rio de Janeiro (RJ), Brazil. Bioactive compounds were analyzed by High Performance Liquid Chromatography (HPLC). Ascorbic acid (74.14 mg 100-1 g-1), lycopene (504 µg g-1) and total carotenoids (632 µg g-1) contents were superior to other fruits rich in these compounds. In fact, E. punicifolia fruits are an excellent source of carotenoids and can be considered a good source of ascorbic acid (vitamin C). Furthermore, its chemical composition has presented phenolic compounds like gallic acid and anthocyanins. Thus, this underutilized Brazilian fruit stands out as a source of bioactive compounds, presenting a good potential as a functional food, especially due to the high content of lycopene.

Resumo Este trabalho teve como objetivo caracterizar alguns dos compostos bioativos do fruto da Eugenia punicifolia (Kunth) DC. para aprofundar o conhecimento do seu potencial funcional. Frutos maduros foram coletados da restinga de Maricá-RJ, Brasil. Os compostos bioativos foram analisados por cromatografia líquida de alta eficiência. Os teores de ácido ascórbico (74,14 mg 100-1 g-1), licopeno (504 µg g-1) e carotenoides totais (632 µg g-1) foram superiores aos de outras frutas ricas nesses compostos. Os frutos de E. punicifolia são uma excelente fonte de carotenoides e podem ser considerados uma boa fonte de ácido ascórbico (vitamina C). Além disso, sua composição química apresentou compostos fenólicos, como ácido gálico e antocianinas. Assim, essa fruta brasileira subutilizada se destaca como fonte de compostos bioativos, apresentando um bom potencial como alimento funcional, principalmente devido ao alto teor de licopeno.

RESUMO: Foi realizado um estudo comparativo com a extração convencional e assistida por ultrassom em resíduos do processamento de tomate. A extração ultrassônica exibiu teor de fenólicos e flavonóides ligeiramente maiores, bem como maior capacidade antioxidante ABTS + (4,63 mg AG.g-1, 0,96 mg RUE.g-1 e 27,90 μmol TE.g -1, respectivamente). Em ambos os extratos, uma alta porcentagem de flavonóides foi perdida durante a digestão simulada, resultando em uma bioacessibilidade de aproximadamente 13%. Os extratos apresentaram boa estabilidade durante as condições de armazenamento, o que indica uma possível aplicação tecnológica.

ABSTRACT: A comparative study was perfomed with conventional and ultrasound assisted extraction on tomato processing waste. Ultrasound extraction exhibited slightly higher phenolic and flavonoids content, as well as higher ABTS + radical scavenging capacity (4.63 mg GAE.g-1, 0.96 mg RUE.g-1 and 27.90 μmol TE.g -1 respectively). On both extracts, a high percentage of flavonoids was lost during simulated digestion, resulting on a bioacessibility of approximately 13 %. Extracts presented good stability during storage conditions, which indicates a possible technological application.

ABSTRACT: Vitamin A deficiency is the third most important micronutrient deficiency having a significant impact on public health worldwide. The aim of this study was to develop a carotenoid extraction process with edible vegetable oils, using a central composite design which, concurrently, enriches the oils with provitamin A carotenoids. The stability of carotenoids in the oil and their shelf life was also evaluated. The process also aimed to meet the Recommended Daily Intake for vitamin A (600 μg retinol equivalent for an adult) with the enriched oil. The results showed that 20 % of the vegetable matrix (dried carrot) in vegetable oil and 5 min of extraction time was an optimum combination for both soy oil (64.43 μg retinol equivalent mL−1) and olive oil (62.98 μg retinol equivalent mL−1). Furthermore, the ingestion of just a spoonful (∼10 mL) of the enriched oils would meet the Recommended Daily Intake for vitamin A (600 μg retinol equivalent), and, thus, it was possible to affirm that a dose of vegetable oils enriched with provitamin A contributes to meeting the Recommended Daily Intake for vitamin A. The proposed process is based on simple and low-cost technology that can be used to enrich edible oils (soybean and olive oil) with provitamin A.

ABSTRACT Acylated anthocyanins from a purple-fleshed sweet potato (PFSP), obtained by organic cultivation in Brazil, were characterized after separation by a high performance liquid chromatography-diode array detector (HPLC-PDA). These anthocyanins were manually collected at the detector output, concentrated and injected into a high resolution mass spectrometer (ESI-QTOF-MS2). Twenty-two acylated anthocyanins were detected. Among them, sixteen had been reported in the literature and six, derived from peonidin were reported for the first time in sweet potato roots in this study. These compounds showed molecular ions with accurate mass/charge ratios (m/z) of 909.2081, 961.3010, 961.2571, 963.3345, 1123.2932 and 1179.3862. Although anthocyanins in PFSP have already been extensively studied, the variety studied in this work is probably genetically different from all varieties and cultivars already researched, which would explain why these anthocyanins have not been observed in the previously studied varieties.

Abstract Mollusks are considered a nutritious source of food and their consumption has increased worldwide. However, their consumption, mainly of bivalves, has been considered responsible for numerous cases of foodborne diseases. This is related to their food intake, as they are filter-feeders and, consequently, bioaccumulate toxic compounds. High hydrostatic pressure (HHP) is recognized as an efficient technology to control pathogenic and deteriorating microorganisms, with low damage to the sensorial and nutritional properties of foodstuffs. This review addresses the use of HHP on bivalve mollusks, based on recent relevant studies in this field.

RESUMO: O objetivo deste trabalho foi avaliar a composição nutricional e compostos bioativos do umbu, incluindo polpa, semente, casca e uma polpa comercial do fruto. Amostras das frações e da polpa comercial foram analisadas para determinação da composição centesimal e mineral, compostos fenólicos totais e capacidade antioxidante. As polpas e casca também foram analisadas quanto aos teores de vitamina C e carotenoides. A polpa comercial apresentou melhor composição nutricional em comparação com a polpa fresca (P<0,05). A casca do fruto apresentou maior teor de compostos fenólicos e capacidade antioxidante que a semente. A casca também se destacou pelos seus teores de vitamina C (79 mg.100 g-1) e carotenoides totais (2.751 µg.100 g-1), mostrando que, como principal barreira do fruto para sua proteção, é uma fração rica em compostos bioativos. Os maiores teores de fibras e ferro foram observados na semente de umbu (P<0,05). Portanto, os subprodutos do despolpamento do fruto podem ser ingredientes adequados para o desenvolvimento de alimentos mais ricos em nutrientes e compostos bioativos.

ABSTRACT: The objective of this research was to evaluate the nutritional composition and bioactive compounds of whole umbu fruit, including pulp, seed and peel, and also of a commercial umbu pulp. Samples of the fractions and of commercial pulp were analyzed for determination of minerals and proximate composition, total phenolic and antioxidant activity. Pulps and peel were also analyzed for vitamin C and carotenoids contents. Commercial pulp presented better nutritional composition than fresh pulp (P<0.05) and the peel presented higher phenolic content and antioxidant activity than seed. Peel also stood out by its vitamin C (79 mg.100 g-1) and total carotenoids (2,751 µg.100 g-1) contents, showing that, as the main barrier of the fruit for its protection, it is a fraction rich in bioactive compounds. The highest dietary fiber and iron contents were observed in umbu seed (P<0.05). Therefore, umbu by-products may be ingredients proper for development of food richer in nutrients and bioactive compounds.

Resumo: O objetivo deste trabalho foi determinar os teores de óleo, proteína, ácidos graxos, isoflavonas e antocianinas, em grãos de soja de diferentes linhagens e estádios de maturação. Foram feitas avaliações quantos aos perfis químicos das linhagens com tegumento preto (BRM09-50995) e amarelo (BRM11-51428 e BRM08-50643), colhidas nos estágios de maturidade R6 (sementes imaturas), R7 (maturidade fisiológica) e R8 (maturação completa). Os teores de óleo e proteína aumentaram do estágio R6 para o R8, e BRM11-51428 apresentou o maior teor de proteína. Os teores de ácidos graxos palmítico, esteárico e linolênico foram maiores em R6, e os teores de ácidos linoleico e oleico foram maiores em R7 e R8, respectivamente. No estágio de crescimento R8, BRM11-51428 e BRM09-50995 apresentaram os maiores teores de ácido oleico e linoleico, respectivamente, e o menor teor de ácido linolênico. Os teores de isoflavonas glicosídeos e agliconas foram maiores em R8, enquanto as formas de malonil foram maiores em R7. Agliconas totais aumentaram cerca de três vezes de R6 para R8. BRM09-50995 apresentou o maior teor de isoflavonas totais e antocianinas, principalmente no estágio R8, o que torna esta linhagem uma opção para processar alimentos funcionais de soja.

Abstract: The objective of this work was to determine the oil, protein, fatty acid, isoflavone, and anthocyanin contents in soybean grains of different breeding lines and maturity stages. Evaluations were performed for the chemical profiles of black- (BRM09-50995) and of yellow-seed-coat (BRM11-51428 and BRM08-50643) breeding lines, harvested at the R6 (immature seeds), R7 (physiological maturity), and R8 (full maturity) maturity stages. Oil and protein contents increased from the R6 to the R8 stage, and BRM11-51428 showed the highest protein content. Palmitic, stearic, and linolenic fatty acids were higher at R6, and linoleic and oleic acids were higher at R7 and R8, respectively. At the R8 growth stage, BRM11-51428 and BRM 09-50995 showed the highest contents of oleic and linoleic acids, respectively, and the lowest content of linolenic acid. The amounts of isoflavone glucosides and aglucones were higher at R8, while malonyl forms were higher at R7. Total aglucones increased about three times from R6 to R8. BRM09-50995 showed the highest content of total isoflavones and anthocyanins, mainly at the R8 stage, which makes this lineage an option to process functional soybean food.

ABSTRACT Edible films are an alternative to synthetic materials used for packaging foods. The aim of this study was to develop and characterize films made from cassava starch, freeze-dried acai and glycerol. The films were characterized for thickness, water vapor permeability, water solubility, anthocyanins, antioxidant capacity and mechanical properties. The results indicated a rich edible film in anthocyanins with considerable antioxidant capacity (150.70 micromol Trolox), which can extend the commercial validity of the packaged food and meets the growing demand for biodegradable packaging that tends to reduce the environmental impact. The addition results in a significant effect on the polymer matrix reducing the water solubility and water activity. The elongation test at rupture reported to be 17.738%, indicating that addition of pulp increased film flexibility.

O consumo de espigas de milho verde com endosperma normal é tradicional, no Brasil, e a sua comercialização in natura é cada vez maior no mercado de produtos minimamente processados, mostrando a necessidade de mais estudos a respeito de sua vida útil. O objetivo deste trabalho foi avaliar a influência de duas atmosferas controladas (2% O2 + 8% CO2, 4% O2 + 8% CO2) e atmosfera ambiente, na qualidade de milho verde, do tipo normal Embrapa HT1, minimamente processado, durante 12 dias de armazenamento, a 5 °C. As atmosferas controladas foram eficientes em reduzir a perda de massa das espigas de milho, apresentando também menores valores de acidez titulável, o que indica menor atividade respiratória. Os sólidos solúveis, os carotenoides totais, a zeaxantina, a firmeza e os teores de glicose, frutose e sacarose foram influenciados somente pelo tempo de armazenamento, com maiores teores de açúcares redutores em relação aos da sacarose durante todo o armazenamento. O valor L* apresentou decréscimo até o oitavo dia de armazenamento, em todas as atmosferas estudadas, com pequeno aumento no controle até o 12º dia. Todas as amostras analisadas, independentemente das atmosferas de conservação, encontravam-se dentro dos limites microbiológicos aceitáveis e seguros para consumo.

The consumption of corn on the cob of normal type is traditional in Brazil. Its commercialization, as fresh product, properly cleaned and packaged, is being offered increasingly in the market as fresh cut corn. Therefore, it is necessary more studies about this kind of products. The aim of this study was evaluated the influence of two different atmospheres (2% O2 + 8% CO2, 4% O2 + 8% CO2) atmosphere and room atmosphere) under 5 °C on the quality of fresh cut corn (Embrapa HT1) on the cob of normal type for 12 days´ storage. The control atmospheres were effective in reducing the weight loss of cobs, which also showed lower values of total titratable acidity, which indicates lower respiratory activity. The soluble solids, total carotenoids, zeaxanthin, firmness and the glucose, fructose and sucrose contents were influenced only by the storage time. It can be verified that concentrations of reducing sugars were higher than the sucrose during the storage. The L* value decreased until 8 days of storage in all the atmospheres studied, with a small increase in control until day 12. All the samples of fresh cut corn studied, independent of the treatment, were within the acceptable microbiologic limits.

In order to generate simple, efficient analytical methods that are also fast, clean, and economical, and are capable of producing reliable results for a large number of samples, a micro scale extraction method for analysis of carotenoids in vegetable matrices was developed. The efficiency of this adapted method was checked by comparing the results obtained from vegetable matrices, based on extraction equivalence, time required and reagents. Six matrices were used: tomato (Solanum lycopersicum L.), carrot (Daucus carota L.), sweet potato with orange pulp (Ipomoea batatas (L.) Lam.), pumpkin (Cucurbita moschata Duch.), watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) and sweet potato (Ipomoea batatas (L.) Lam.) flour. Quantification of the total carotenoids was made by spectrophotometry. Quantification and determination of carotenoid profiles were formulated by High Performance Liquid Chromatography with photodiode array detection. Microscale extraction was faster, cheaper and cleaner than the commonly used one, and advantageous for analytical laboratories.

Romã (Punica granatum L.) é um fruto com um longo histórico medicinal, especialmente devido aos compostos fenólicos presentes em sua composição, como as antocianinas, as quais são relatadas como um dos mais importantes antioxidantes naturais. A análise de antocianinas por Cromatografia Líquida de Alta Eficiência (CLAE) pode ser considerada uma ferramenta importante para avaliar a qualidade do suco de romã. Para os laboratórios de pesquisa, o maior desafio para a análise quantitativa pela técnica de CLAE é a aquisição de padrões analíticos de alta pureza, uma vez que eles são caros e, em alguns casos, não se encontram disponíveis comercialmente. O objetivo deste estudo foi obter padrões analíticos para a análise qualitativa e quantitativa de antocianinas da romã. Cinco matrizes vegetais (flor de romã e frutos de jambolão, jabuticaba, amora e morango) foram usadas para isolar cada uma das seis antocianinas presentes no fruto da romã, usando a escala analítica com detecção não destrutiva, sendo possível usá-las posteriormente como padrões analíticos. Além disso, as suas identidades foram confirmadas pela técnica de espectrometria de massa de alta resolução. O procedimento proposto mostrou que é possível obter padrões analíticos de antocianinas com elevado grau de pureza (98,0%-99,9%) a partir de fontes naturais e provou ser uma estratégia econômica para os laboratórios que necessitam adquirir padrões, de acordo com as necessidades de suas pesquisas.

Pomegranate (Punica granatum L.) is a fruit with a long medicinal history, especially due to its phenolic compounds content, such as the anthocyanins, which are reported as one of the most important natural antioxidants. The analysis of the anthocyanins by high performance liquid chromatography (HPLC) can be considered as an important tool to evaluate the quality of pomegranate juice. For research laboratories the major challenge in using HPLC for quantitative analyses is the acquisition of high purity analytical standards, since these are expensive and in some cases not even commercially available. The aim of this study was to obtain analytical standards for the qualitative and quantitative analysis of the anthocyanins from pomegranate. Five vegetable matrices (pomegranate flower, jambolan, jabuticaba, blackberry and strawberry fruits) were used to isolate each of the six anthocyanins present in pomegranate fruit, using an analytical HPLC scale with non-destructive detection, it being possible to subsequently use them as analytical standards. Furthermore, their identities were confirmed by high resolution mass spectrometry. The proposed procedure showed that it is possible to obtain analytical standards of anthocyanins with a high purity grade (98.0 to 99.9%) from natural sources, which was proved to be an economic strategy for the production of standards by laboratories according to their research requirements.

Two analytical methods for the determination and confirmation of ochratoxin A (OTA) in green and roasted coffee samples were compared. Sample extraction and clean-up were based on liquid-liquid phase extraction and immunoaffinity column. The detection of OTA was carried out with the high performance liquid chromatography (HPLC) combined either with fluorescence detection (FLD), or positive electrospray ionization (ESI+) coupled with tandem mass spectrometry (MS-MS). The results obtained with the LC-ESI-MS/MS were specific and more sensitive, with the advantages in terms of unambiguous analyte identification, when compared with the HPLC-FLD.

Um método utilizando Cromatografia Líquida de Alta Eficiência-Espectrometria de Massas Sequencial (CLAE-EM/EM) com curva de calibração em matriz foi desenvolvido e validado para a determinação de ocratoxina A (OTA) em café verde. A linearidade foi demonstrada entre 3,0 e 23,0 ng.g-1. As recuperações médias variaram entre 90,45% e 108,81%; o desvio padrão relativo sob condições de repetitividade e precisão intermediária foram de 5,39% e 9,94% e de 2,20% e 14,34%, respectivamente. Os limites de detecção e quantificação foram 1,2 ng.g-1 e 3,0 ng.g-, respectivamente. O método desenvolvido foi adequado, contribuiu para o campo de análises em micotoxinas e será usado para a futura produção de Material de Referência Certificado (MRC) para OTA em café.

A method using Liquid Chromatography Tanden Mass Spectrometry (LC-MS/MS) with matrix-matched calibration curve was developed and validated for determining ochratoxin A (OTA) in green coffee. Linearity was found between 3.0 and 23.0 ng.g-1. Mean recoveries ranged between 90.45% and 108.81%; the relative standard deviation under repeatability and intermediate precision conditions ranged from 5.39% to 9.94% and from 2.20% to 14.34%, respectively. The limits of detection and quantification were 1.2 ng.g-1 and 3.0 ng.g-¹, respectively. The method developed was suitable and contributed to the field of mycotoxin analysis, and it will be used for future production of the Certified Reference Material (CRM) for OTA in coffee.

A validade comercial de sardinhas das espécies Sardinella brasiliensis e Cetengraulis edentulus mantidas sob refrigeração em gelo (0+2°C) foi determinada por parâmetros analíticos físico-químicos, bacteriológicos e sensorial. Nas duas amostras, os teores de Bases Voláteis Totais (BVT) e Trimetilamina (TMA) atingiram o limite máximo recomendado na legislação (30mg N100g-1 para BVT e 4mg N100g-1 para TMA) após 14 e 8 dias de estocagem, respectivamente. O conteúdo de histamina, putrescina e cadaverina se manteve em níveis inferiores a 2.0µg g-1 nas duas amostras durante o período de estocagem. A produção de hipoxantina variou de 0,65 a 2,62µmol g-1 nas amostras de S. brasiliensis e de 1,40 a 2,09µmol g-1 nas amostras de C. edentulus. A contagem inicial de Enterobacteriaceae foi de 3,81log UFC g-1 e 3,82log UFC g-1 atingindo, ao final de 18 dias de estocagem, 6,57log UFC g-1 e 6,87log UFC g-1, nas amostras de S. brasiliensis e C. edentulus, respectivamente. Para as contagens de bactérias heterotróficas aeróbias mesófilas e psicrotróficas, o limite de 7log UFC g-1 preconizado na legislação internacional foi alcançado após o 12° e 8° dias de estocagem nas amostras de S. brasiliensis e após o 12° e 6° dias de estocagem nas amostras de C. edentulus, respectivamente. O método de índice de qualidade sugeriu, para as amostras de S. brasiliensis, um limite de consumo aceitável inferior a 11 e, para as amostras de C. edentulus, um limite de aceitabilidade inferior a 14. Foi proposta a validade comercial de dez dias para a S. brasiliensis e nove dias para o C. edentulus.

Theshelf life of sardines of Sardinella brasiliensis and Cetengraulis edentulus species kept on ice at +2°Cwas determined by physical-chemical, bacteriological and sensory parameters. In both samples, the levels of Total Volatile Bases (TVB) and Trimethylamine (TMA) reached the limits recommended by law (30mg N 100g-1 for TVB and 4mgN100g-1 for TMA) after 14 and 8 days of storage, respectively. The contents of histamine, putrescine and cadaverine remained at levels below 2.0µg g-1 in both samples during the storage period. The hypoxanthine production ranged from 0.65 to 2.62µmol g-1 in samples of S. brasiliensis and 1.40 to 2.09µmol g-1 in samples of C. edentulus. The initial count of Enterobacteriaceae was 3.81logCFU g-1 and 3.82logCFU g-1 reaching, after 18days of storage, 6.57logCFU g-1 and 6.87logCFU g-1, in samples of S. brasiliensis and C. edentulus, respectively. For heterotrophic bacteria aerobic mesophilic and psychrotrophic count the limit of 7logCFU g-1 recommended by international legislation was reached after12 and 8days of storage in samples of S. brasiliensis and after 12 and 6days of storage in samples of C. edentulus, respectively. The quality index method suggested for samples of S. brasiliensis, a limit of acceptable consumption less than 11 and for samples of C. edentulus a limit of acceptability below 14. As a result of this study, we recommend a shelf life of ten days for the S. brasiliensis and nine days for the C. edentulus.

A farinha de batata-doce, quando elaborada a partir de raízes com alto teor de β-caroteno, é fonte de pró-vitamina A, que apresenta efeitos benéficos na saúde humana. Visando contribuir com o suprimento de vitamina A na alimentação de populações carentes, a EMBRAPA tem selecionado e melhorado culturas via biofortificação, como da batata-doce, e pesquisado o desenvolvimento de produtos com esta matéria-prima biofortificada. Complementando esses desenvolvimentos, o objetivo deste estudo foi comparar o efeito do tipo de embalagem e do sistema de acondicionamento do produto na preservação de carotenoides de farinha de batata-doce biofortificada. A farinha foi acondicionada com e sem vácuo, em embalagens com diferentes barreiras ao oxigênio, vapor d'água e luz (PET/Al/PEBD, PETmet/PEBD, PEBD/PA/PEBD e PEBD) e estocada a 25 °C/75%UR com e sem exposição à luz por um ano. Perdas de 50% de carotenoides totais e β-caroteno ocorreram na farinha em PETmet/PEBD e PEBD sem vácuo, aos 50 dias de estocagem, em razão do teor de oxigênio residual presente no espaço livre e também da alta permeação de oxigênio pelo material no caso do PEBD, no qual a composição do ar foi mantida durante todo o estudo. Perdas de 50% de carotenoides ocorreram aos 90 dias com ou sem exposição à luz no produto em PEBD/PA/PEBD com vácuo, indicando que a reação de oxidação de carotenoides sob luz se restringe apenas à farinha em contato com a superfície da embalagem. Sob vácuo e em PETmet/PEBD, os teores de carotenoides na farinha diminuíram ligeiramente e foram mantidos no PET/Al/PEBD, até 360 dias de estocagem. Os resultados indicaram que a redução do teor de oxigênio no espaço livre da embalagem por meio da aplicação de vácuo aliada ao uso de materiais de embalagem com barreira ao oxigênio da ordem de grandeza de PET com metalização barreira são os fatores mais importantes na preservação de carotenoides em farinha de batata-doce biofortificada.

Sweet potato flour, when made from roots with high β-carotene contents, is a source of pro-vitamin A, presenting beneficial effects for human health. Thus aiming at contributing to the supply of vitamin A in the diet of more needy populations, EMBRAPA has selected and improved some crops via biofortification, such as the sweet potato, and developed products with the biofortified raw material. Complementing these developments, the purpose of this study was to correlate the effect of the type of package and packaging system on the product, in the preservation of the carotenoids in the biofortified sweet potato flour. The flour was packed with and without vacuum in packs with different oxygen, water vapour and light barriers (PET/Al/LDPE, PETmet/LDPE, LDPE/PA/LDPE and LDPE) and stored at 25 °C/75%RH with and without exposure to light. Losses of 50% of the total carotenoids and β-carotene occurred in the flour packed in PETmet/LDPE and LDPE without vacuum after 50 days of storage, due to the residual oxygen in the headspace and the high oxygen transmission rate in the case of LDPE, where the internal atmosphere showed the composition of air throughout the study. Losses of 50% carotenoids occurred after 90 days with and without exposure to light in the flour packed in LDPE/PA/LDPE with vacuum, indicating that in the presence of light, the carotenoid oxidation reaction is restricted to flour in contact with the surface of the package. Under vacuum and packed in PETmet/LDPE, the carotenoid contents of the flour reduced slightly, but were preserved for up to 360 days of storage when packed in PET/Al/LDPE. The results indicate that the key factors to preserve carotenoids in biofortified sweet potato flour are the reduction of the oxygen level in the headspace of the package by the application of vacuum, together with the use of packaging materials with an oxygen barrier as good as that of PET with a metalized barrier.