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

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/

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/