451 research outputs found
Desarrollo de métodos analíticos para el estudio en alimentos de fenómenos de oxidación lipídica y migración provenientes del material de envase
Textos en inglés e castelánEl gran desarrollo de la industria alimentaria ha supuesto un
notable avance en lo que se refiere a la conservación y ha puesto a
disposición de los consumidores nuevas técnicas de conservación
(pasteurización, liofilización y ultracongelación).
Una de las causas más comunes de deterioro de los alimentos
durante el almacenamiento es la oxidación lipídica. En los últimos años
este fenómeno ha suscitado un gran interés por parte de los investigadores
y de la opinión pública debido a su potencial influencia en el proceso de
envejecimiento y en varias enfermedades como la arteriosclerosis y el
cáncer
Active Edible Packaging
This article belongs to the Section Material Sciences.Definition: Active edible packaging is a food packaging made of comestible bioproducts and active
compounds that interacts with the food. The bioproducts, usually biopolymers, must be recognized
as safe and with characteristics to be consumed by humans—comestible—and not toxic and capable
of carrying an active compound, like anti-browning agents, colorants, flavors, nutrients, antimicrobial
and/or antioxidant compounds, in order to extend the product shelf-life, reduce contamination and
maintain or even enhance the nutritional value.This work was supported by UIDB/04077/2020 and UIDB/00211/2020 with funding from
FCT/MCTES. This research was also supported by the PANACEA project that has received funding
from the European Union’s Horizon 2020 Research and Innovation program under Grant Agreement
773501.info:eu-repo/semantics/publishedVersio
Extending poultry meat shelf life through the application of Cyanara cardunculus L. leaf extracts
Cynara cardunculus L. (Asteraceae), commonly named cardoon, is a multipurpose crop that includes three varieties, the globe artichoke (var. scolymus (L.) Fiori), the cultivated cardoon (var. altilis DC.), and the wild cardoon (var. sylvestris (Lamk) Fiori). Its flower is normally used as vegetal rennet in the production of some cheeses and its leaves, the main by-product generated, are known for its excellent antioxidant and antimicrobial activities1. These properties may be an asset in the food industry as cardoons’ leaves may be used to delay lipid oxidation and microbial growth, thus prolonging foods’ shelf life.
Therefore, this study aims to evaluate the effectiveness of cultivated cardoon leaves and the globe artichoke leaves ethanolic extracts, on poultry meat preservation. Poultry meat was mixed with the different extracts at a concentration of 1% (w/w) and stored under refrigeration (5°C ± 2°C) for 15 days. The microbiological growth was evaluated through the assessment of the total mesophilic aerobic microorganisms, total psychrotrophic aerobic microorganisms, and Enterobacteriaceae. The physicochemical characterization was evaluated through moisture, pH, acidity, colour and Total Volatile Basic Nitrogen (TVBN), and the lipid oxidation by Thiobarbituric Acid Reactive Substances (TBARS).
Both extracts were effective in retarding microbial growth by maintaining constant pH and level of acidity. After 15 days, poultry meat with both extracts showed a difference up to 11 log CFU/g to control samples (without extract). Also, both extracts were able to reduce the lipid oxidation of the poultry meat when compared to the control samples, at the end of the assay. The colour of extracts can be a limitation due to the greenish-yellow colour that is seen in the meat, although it was more evident in the sample with the cardoon extract. Overall, cardoon extract was the most effective in extending poultry meat shelf life.Cássia H. Barbosa thanks the Fundação para a Ciência e Tecnologia (FCT), Portugal for the Ph.D. Grant
2021.08154.BD. The authors would like to thank the company NINA, Lda, for kindly supplying the cardoon leaves. This work was financially supported by the Mechanical Engineering and Resource Sustainability Center—MEtRICs, which is financed by national funds from the FCT/MCTES (UIDB/04077/2020 and UIDP/04077/2020).info:eu-repo/semantics/publishedVersio
Exploring Cyanara cardunculus L. potential for the food industry: the antioxidant pattern
Cynara cardunculus L. (cardoon) is a versatile perennial crop indigenous to the Mediterranean region that has three botanical varieties including wild cardoon (var. sylvestris (Lamk) Fiori), cultivated cardoon (var. altilis DC.), and globe artichoke (var. scolymus (L.) Fiori). Cardoon is mostly renowned for its flower, which is used to coagulate milk in the production of soft cheeses, with the leaves serving as the primary by-product. The bioactive compound-rich leaves are employed in traditional medicine and have interesting antioxidant and antimicrobial properties1. Cardoon leaves may therefore be used in the food sector to prolong the shelf life of foods by preventing lipid oxidation and microbiological growth.
This study aims to evaluate the antioxidant capacity, through DPPH free radical scavenging and the β-carotene bleaching assays, and total phenolic compounds content (TPC) and total flavonoids content (TFC) of cultivated cardoon and globe artichoke leaves extracts, both methanolic and ethanolic.
Cardoon extracts, both ethanolic (2.1 mg/mL) and methanolic (0.8 mg/mL), presented lower EC50 than artichoke extracts (EC50EtOH= 3.9 mg/mL; EC50MeOH= 1.6 mg/mL), which means greater antioxidant capacity. For the β-carotene assay, cardoon extract (AACEtOH:448.06; AACMeOH:279.67) presented a higher antioxidant capacity coefficient (AAC) than the artichoke extract (AACEtOH:90.98; AACMeOH:114.97). Accordingly, cardoon extracts (EtOH: 81.98 mg GAE/g; MeOH: 112.84 mg GAE/g) also had a higher content of TPC than artichoke (EtOH: 49.14 mg GAE/g; MeOH: 29.79 mg GAE/g). The same can also be observed for TFC, where cardoon (EtOH: 145.47 mg ECE/g; MeOH: 129.27 mg ECE/g) presented greater total flavonoids content than artichoke (EtOH: 81.33 mg ECE/g; MeOH: 21.24 mg ECE/g).These results confirm that cardoon leaves are a natural source of antioxidant compounds that can be exploited by the food industry.This work was financially supported by the Mechanical Engineering and Resource Sustainability Center—MEtRICs, which is financed by national funds from the FCT/MCTES (UIDB/04077/2020 and UIDP/04077/2020). Cássia H. Barbosa thanks the Fundação para a Ciência e Tecnologia (FCT), Portugal for the Ph.D. Grant
2021.08154.BD.info:eu-repo/semantics/publishedVersio
Determination of ergosterol in oyster mushroom (Pleurotus ostreatus) cultivated in coffee grounds and wheat straw
Um dos cogumelos comestíveis que tem suscitado maior interesse nos últimos
anos é o Pleurotus ostreatus, conhecido como cogumelo ostra, devido
à facilidade de cultivo e ao seu grande potencial económico e qualidade
nutricional. Existe, assim, a necessidade de estudar a sua composição em
nutrientes e compostos bioativos para valorizar o seu cultivo. Este estudo
teve por objetivo determinar o teor de ergosterol, por Cromatografia Líquida
de Alta Eficiência acoplada a detetor de Ultravioleta-Visível, do cogumelo
Pleurotus ostreatus cultivado em diferentes substratos, nomeadamente,
borras de café e palha de trigo. Verificou-se que as amostras de cogumelo
P. ostreatus cultivadas em borras de café apresentaram uma concentração
de ergosterol superior (4,06 ± 0,32 mg/g de matéria seca) relativamente
às amostras da mesma espécie de cogumelo cultivadas em palha de trigo
(3,34 ± 0,19 mg/g de matéria seca). O uso das borras de café no substrato
de crescimento de cogumelos ostra permitiu um aumento da concentração
de ergosterol. No futuro seria de todo o interesse avaliar a influência do uso
deste subproduto no substrato de crescimento de outras espécies comestíveis
de cogumelos e no teor de outros compostos bioativos.One of the edible mushrooms that have attracted more interest in recent
years is Pleurotus ostreatus, known as the oyster mushroom, due to the
ease of cultivation and its great economic potential and nutritional quality.
Therefore there is the need to study its composition in nutrients and bioactive
compounds to enhance its cultivation. This study aimed to determine
the ergosterol content by high-performance liquid chromatography
coupled to the ultraviolet-visibilize detector of Pleurotus ostreatus mushroom
grown on different substrates, namely coffee grounds and wheat
straw. Samples of P. ostreatus mushroom cultivated in coffee grounds
showed a higher concentration of ergosterol (4.06 / g ± 0.32 mg dry matter)
than the samples of the same species of mushroom grown on wheat
straw (3.34 / g ± 0.19 mg dry matter). The use of coffee grounds on the
oyster mushroom growth substrate allowed obtaining an increase in ergosterol
concentration. In the future it would be of great interest to evaluate
the influence of the use of this by-product on the growth substrate
of other edible mushrooms species and on the content of other bioactive
compounds.info:eu-repo/semantics/publishedVersio
A LC/UV/Vis method for determination of cyanocobalamin (VB12) in multivitamin dietary supplements with on-line sample clean-up
A HPLC-UV/Vis method using a two-column strategy with a switching valve for on-line sample cleanup
was developed for the determination of cyanocobalamin (CN–Cbl/Vitamin B12) in multivitamin
dietary supplement tablets. The method uses two columns: an Agilent Zorbax C8 (150 mm 4.6 mm, 5
mm particle size) reversed-phase column and a Waters Symmetry C18 (150 mm 4.6 mm, 5 mm particle
size) reversed-phase column. Chromatographic separation was achieved using a programmed gradient
mobile phase consisting of (A) 0.1% formic acid in water and (B) 0.1% formic acid in acetonitrile.
Because of the low levels of Vitamin B12 in the samples, large injection volumes, and thus much
interfering material, must be used to exceed the limit of quantitation (LOQ) by UV detection. A
switching valve was used to divert most of these early eluting interfering materials to waste, effecting
on-line sample clean-up without excessive sample preparation steps. The recovery of CN–Cbl in the
method was 99.5% and the LOQ was 10 ng per injection. The method was successfully applied to the
analysis of the NIST SRM 3280 multivitamin/multimineral dietary supplement tablet. The method is
specific, precise, and accurate for the intended use. Compared to off-line sample clean-up procedures, it
offers the advantage of being easier, more economical, and less time-consuming
Nova geração de embalagens alimentares pretende aumentar a vida útil dos alimentos
O Instituto Nacional de Saúde Doutor Ricardo Jorge (Instituto Ricardo Jorge) tem em curso um projeto de investigação que visa desenvolver uma embalagem biodegradável para aumentar a vida útil dos alimentos.
Com o acrónimo de “Rose4Pack”, os investigadores têm pela frente um importante desafio na área da nova geração de embalagens alimentares.Projeto Rose4Pack (PTDC/AGR-TEC/ 3366/2012
Arquitectura religiosa moderna em Portugal : o caso do Atelier de Nuno Teotónio Pereira
Revista arquitectura Lusíada. - ISSN 1647-9009. - N. 8 (2.º semestre 2015). - p. 153-167O presente artigo tem como objecto de estudo a arquitectura dos espaços de culto cristão. Para tal, foram eleitas duas tipologias de Igreja concebidas pela equipa do Atelier de Nuno Teotónio Pereira ao longo do século XX que se constituem como modelos exemplares: a Igreja Rural: Igreja de Águas em Penamacor; a Igreja Urbana: Igreja do Sagrado Coração de Jesus em Lisboa.
O sucesso que estas obras conquistaram deve-se não só ao atelier que as executou como também à influência do Movimento para a Renovação da Arte Religiosa empenhado em elevar a dignidade e qualidade plástica da arquitectura e da arte sacra em Portugal. A sua importância deve-se ao facto de terem influenciado uma nova geração de arquitectos portugueses empenhados em reivindicar uma arquitectura verdadeiramente moderna – não só de cariz religioso – cujos princípios se constituíram como a charneira da mudança de que resultou a contemporaneidade.The present article has the Christian worship architecture as subject of study. To do that, were elected two typologies of churches designed by Nuno Teotónio Pereira’s studio during the twentieth century to act as case studies: The Rural church: Águas Church in Penamacor; The Urban church: Sacred Heart of Jesus church in Lisbon.
The success of these buildings was achieved not only due to the office who conceived them, but also because of the influence of the Movement for the renovation of Religious Art, committed to raise the dignity and plastic quality of the sacred art and architecture in Portugal. It’s significance due to the fact that they actually influenced a new generation of Portuguese architects, focused in the claiming of a truly modern architecture – not just the religious one – whose principles were the hinge of the change which led to contemporaneity
Perfil lipídico de frutos secos e sementes
Este trabalho foi financiado
pelo INSA no âmbito do projeto “PTRANSALT - Avaliação de ácidos
gordos trans, gordura saturada e sal em alimentos processados: estudo do
panorama português (2012DAN828)” e do projeto “SeeDNuT – Benefícios
para a saúde associados ao consumo de sementes oleaginosas e frutos
secos, com base na determinação do perfil lipídico (2012DAN723)”
Bisfenol A (BPA)
Poster de divulgação sobre Bisfenol A (BPA) informando sobre: O que é? Onde pode estar presente? Efeitos na saúde; Como ocorre a contaminação dos alimentos? Prevenção.Este trabalho foi realizado no âmbito do projeto “Desenvolvimento de
metodologias de avaliação de constituintes de embalagens alimentares poliméricas e
determinação das suas propriedades estruturais e mecânicas”, financiado pelo Instituto
Nacional de Saúde Doutor Ricardo Jorge, I.P.N/
- …