101 research outputs found
Pesticidas
Aula leccionada no INSA, em Maio de 2011, no âmbito do "Mestrado em Biologia Humana e Ambiente", da Faculdade de Ciências da Universidade de Lisboa, e inserida na cadeira de Toxicologia e Saúde
VIPACFood: valorização de subprodutos alimentares para desenvolvimento de filmes e revestimentos que visem aumentar a vida útil de alimentos
O projeto VIPACFood é o acrónimo de “Valorization of Industrial fruits by Products and algae biomass waste: Development of Active Coatings to extend Food shelf life and reduce food losses”. Trata-se de um projeto de 3 anos que teve início no dia 1 de Junho de 2017 e é financiado pelo ARIMNet2. O consórcio do projeto é formado por oito organizações de investigação e governamentais, abrangendo quatro países, Tunísia, Itália, Portugal e Espanha. O coordenador é a Doutora Khaoula Khwaldia (National Institute of Research and Physicochemical Analysis, Tunísia).
O projeto visa desenvolver tecnologias pós-colheita seguras e acessíveis que conduzam à redução de perdas, à melhoria da segurança alimentar e prazo de validade, reduzindo a quantidade de embalagem usada para preservar os alimentos, das quais resultam benefícios sociais, ambientais e económicos.
O projeto também tem o objetivo de valorizar subprodutos industriais de frutas e resíduos de biomassa de algas, extraindo componentes ativos e funcionais com elevado valor e pela conceção de novos produtos transformados com grande apelo, estabilidade e potencialidade de comercialização que pode ajudar na redução dos subprodutos e resíduos eliminados e terá um impacto positivo na sustentabilidade das indústrias de transformação.
Além de aumentar a eficiência económica e aumentar a competitividade dos produtores locais e das pequenas e médias empresas, espera-se que o projeto tenha impacto ambiental e na saúde devido à valorização de subprodutos, à redução significativa dos resíduos alimentares e à melhoria da qualidade dos alimentos e vida útil dos mesmosO presente trabalho insere-se no projeto VIPACFood. Este projeto é financiado pelo ARIMNet2 (Coordination of Agricultural Research in the Mediterranean; 2014-2017), uma ação ERA-NET financiada pela União Europeia (7º Programa Quadro).N/
Lipid oxidation of a meat product packaged with poly (lactic acid)/clay nanocomposites
Introduction: Polylactic acid or polylactide (PLA, Poly) is a biodegradable
thermoplastic aliphatic polyester derived from renewable resources, such as corn starch,
tapioca roots, chips or starch, or sugarcane.
Biopolymer nanocomposites are of great interest to the packaging industry as they can
overcome the limitations of biopolymers compared to synthetic polymers. In the last
two decades, the nanocomposites have been studied intensively, once the addition of
fillers such as organoclays, in particular, montmorillonite (MMT), can improve
rheological, thermal and mechanical properties of the biopolymers (Jollands M. et al.
2010). The presence of MMT can lead to materials which generally exhibit great
property enhancements, mainly due to its intercalation or exfoliation into the polymer
chains.
In this work, PLA was incorporated with 5% (w/w) Cloisite Na+ prepared through a
two-step process: first extrusion of pellets and secondly melted matter was pressed. The
nanocomposite was used to pack a model food (salami) in order to evaluate of the
ability of the new packaging to inhibit lipid oxidation. Thiobarbituric Acid Reactive
Substances (TBARS) assay was used to evaluate the lipid oxidation stage. This assay
allows to measure malondialdehyde (MDA) content, which is formed in the lipid
oxidation of polyunsaturated fatty acids.
Material and Methods: Packaged salami was homogenized with trichloroacetic acid (10
%) in 0.02 M of orthophosphoric acid and the solution was filtered. The filtered solution
was homogenized with thiobarbituric acid aqueous solution (0.02 M) and heated at 100
°C for 40 min. Solutions were cooled down and absorbance was measured at 530 nm.
Results were expressed as mg MDA per kg of salami.
Results and Discussion: Salami slices were packaged with a control film and with the
nanocomposite and analysed at initial time and after 15, 30, 60 and 90 days of contact.
Results showed that salami packaged with the nanocomposite presented lower amount
of MDA after all contact periods, except after 60 days, where there were no differences
between control and nanofilm.
Conclusion: Although the results showed that the new nanocomposite tends to reduce
the production of MDA, further studies should be carried out to confirm the inhibition
of lipid oxidation, such as the peroxide index, p-anisidine value, or the monitorization
of a lipid oxidation indicator like hexanal.Project “Development of methodologies for the evaluation of polymeric food packaging components and determination of their structural and mechanical properties” (2016DAN 1289)N/
Monitorization of hexanal as lipid oxidation indicator in a processed meat product packaged with poly(lactic acid)/clay nanocomposite films
One of the most detrimental processes in fatty foodstuffs is lipid oxidation, which occurs during production and storage,
and influences food composition and safety. Through the analysis of volatile lipid oxidation products we can have an
insight into the oxidation, and some volatiles, such as hexanal, which can be markers of undergoing oxidation
processes. Hexanal is formed when fatty acids are oxidized and is one of many well-documented aromatic components
that contributes to flavour and aroma in common food products containing fatty acids.
During the last decade, the interest in polymer layered silicate (PLS) nanocomposites has rapidly increased due to their
potential for enhancing physical, chemical, and mechanical properties of conventional materials. Polymer
nanocomposites are represented by a polymeric matrix reinforced with nanoscale fillers, among them the most common
silicate clays are represented by montmorillonite (MMT), which is naturally occurring and readily available in large
quantities.
The presence of MMT can lead to materials which generally exhibit great property enhancements, mainly due to its
intercalation or exfoliation into the polymer chains. In this work natural MMT Cloisite Na+ was incorporated in PLA.
The PLA/Cloisite® Na+ films were prepared through a two-step process. In the first step, PLA pellets were fed into a corotating
laboratory twin-screw extruder at 170 °C and 50 rpm for 2 min. Subsequently, Cloisite® Na+ powder (5%, w/w)
were added and mixed. After extrusion, the melted matter was then pressed with a P300P hot press at 170 °C and 100
bar to obtain the PLA/Cloisite® Na+ films. Salami slices were packaged with PLA-OMMT film and with a control film
(PLA). After different storage times (0, 15, 30, 60 and 90 days), salami slices were analysed regarding their hexanal
content. The hexanal derivatization was performed in a solution of 2,4-dinitrophenylhydrazine in sulfuric acid during 4
h in the dark, and the hexanal extraction was performed with n-hexane and evaporation till dryness. The residue was
dissolved in methanol, filtered and analysed. The quantification of hexanal was performed by Ultra High Performance
Liquid Chromatography coupled with Diode Array Detector at 365 nm, with a Pre-column AcquityTM UPLC® BEH C18
(2.1 x 5 mm, 1.7 μm particle size) and a column AcquityTM UPLC® BEH C18 (2.1 × 50 mm, 1.7 μm particle size), the
mobile-phase was acetonitrile-water (75:25, v/v).
The amount of hexanal in packaged salami decreased in the first 60 days of storage. In this period of time the hexanal
content of the salami packaged with the PLA/Cloisite® Na+ films was lower than the salami packaged with control film,
except after 15 days of storage, where there was no difference between two films. After 90 days of storage, the amount
of hexanal in the samples increased, although it was higher in the samples packaged with control film (94.7 ± 6.02
μg/100g salami) than salami packaged with PLA/Cloisite® Na+ films (65.1 ± 6.12 μg/100g salami).
The presence of MMT in the polymer film can reduce the lipid oxidation of processed meat products, extending their
shelf life. Further studies to evaluate differences between PLA and the nanocomposite (PLA-5%Cloisite®Na+) in what
regards to the mechanical and barrier properties are in progress.This work was supported by the research project “Labelling and tracking of nanoclay from food packaging
nanocomposites: a food safety issue – NanoPack4Food” (2014DAN1019) under the Cooperative Programme of the Agreement on Scientific Cooperation between National Research Council of Italy (CNR) and Foundation for Science and Technology of Portugal (FCT)N/
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
Alimentos PT.ON.DATA - Contaminantes químicos na cadeia alimentar em Portugal em amostras do controlo oficial
A recolha de dados analíticos de géneros alimentícios e alimentos para animais é uma importante tarefa da Autoridade Europeia para a Segurança dos Alimentos (EFSA) e uma componente essencial na avaliação do risco associado à alimentação. Os Estados Membros (EM) têm o dever de transmitir para a EFSA os resultados do Controlo Oficial sendo os contaminantes químicos (CQ) uma das áreas a reportar. Os CQ podem estar presentes nos alimentos devido à contaminação ambiental, processo de fabrico, manipulação e transporte e, mesmo quando presentes em quantidades abaixo dos limites legais, o seu efeito cumulativo poderá trazer consequências graves para a saúde humana e animal.
Para melhorar a comparabilidade técnica dos dados que recebe e analisa, a EFSA desenvolveu um modelo de dados Standard Sample Description (SSD), de utilização obrigatória para a transmissão de dados pelos EM. O INSA, em colaboração com várias entidades nacionais competentes para o Controlo Oficial, desenvolveu o sistema alimentos PT.ON.DATA para recolha, validação, transformação em modelo SSD e criação de ficheiros em formato XML para transmissão para a EFSA dos dados de CQ. O sistema criado permitiu ainda concentrar e harmonizar os dados produzidos pelas diversas entidades competentes, possibilitando uma melhor utilização dos mesmos.
O sistema possui dados de contaminantes químicos do controlo oficial desde 2009 existindo atualmente 17149 resultados de géneros alimentícios (47,9 %) e 18644 resultados de alimentos para animais (52,1 %), distribuídos por quatro grupos de CQ, dos quais: 4618 (12,9%) para o grupo de contaminantes do processo, maioritariamente dioxinas e PCBs; 613 (1,7 %) para o grupo de contaminantes ambientais, sobretudo histamina (incluída no grupo das toxinas desde 2012) e hidroximetilfurfural; 18531 (51.8 %) para o grupo das toxinas, maioritariamente aflatoxinas (B1, B2, G1, G2); e 12031 (33,6 %) para o grupo dos metais e substâncias inorgânicas, maioritariamente cádmio, chumbo e mercúrio.EFS
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
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
The influence of cultivated cardoon and globe artichoke ethanolic leaf extracts on the shelf life of poultry meat
Food additives are commonly used to prolong the shelf life of food by slowing down natural deterioration.
However, synthetic additives have raised health concerns despite the European Union's strict
regulations. To address this issue, researchers are exploring natural sources of compounds that can be
safely used as food additives. Extracts from plants and agro-industrial by-products, such as Cynara
cardunculus L. (cardoon), are being investigated for their potential as natural food preservatives.
Cardoon leaves, the main by-product generated, are rich in antioxidants and antimicrobials, making
them a promising candidate. The ethanolic extracts from cultivated cardoon and globe artichoke leaves
were tested for their effectiveness in extending the shelf life of refrigerated poultry meat at a temperature
of 5 ºC. After different storage durations (0, 4, 8, 11, and 15 days), the samples were evaluated for lipid
oxidation, moisture, colour, pH, acidity, total volatile basic nitrogen, and microbial growth.
It was found that the addition to poultry meat of cultivated cardoon leaf extract exhibited the most
negligible malondialdehyde value, indicating significant antioxidant capacity and a significant delay in
lipid oxidation. The extracts were also effective in retarding microbial growth once the counts remained
at initial levels for all microorganisms studied. The results showed that both extracts effectively
preserved the meat's quality for up to 15 days, making them a promising natural alternative to synthetic
additives.Funding: 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). The work was also supported by UIDB/00211/2020 with funding from FCT/MCTES.N/
Applying Cynara cardunculus L. leaf extracts to increase poultry meat shelf life
Cardoon, Cynara cardunculus L. (Asteraceae), is a multipurpose crop. Its flower is used as vegetal rennet in the production of some cheeses, and its leaves, the main by-product generated, have excellent antioxidant and antimicrobial activities. 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. This study aims to evaluate the effectiveness of cultivated cardoon and globe artichoke leaf ethanolic extracts on poultry meat preservation. Extracts were mixed with the poultry meat (1% w/w) and stored under refrigeration (5°C ± 2°C) for 15 days. The microbiological growth was evaluated as well as moisture, pH, acidity, colour, Total Volatile Basic Nitrogen (TVBN), and lipid oxidation by Thiobarbituric Acid Reactive Substances (TBARS). Both extracts were effective in retarding microbial growth by maintaining a constant pH and level of acidity. After 15 days, poultry meat with both extracts showed a difference of up to 11 log CFU/g compared 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 the shelf life of poultry meat.Funding: 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
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