Browsing by Author "Silva, Ana Sanches"
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- Active Flexible Films for Food Packaging: A ReviewPublication . Azevedo, Ana G.; Barros, Carolina; Miranda, Sónia; Machado, Ana Vera; Castro, Olga; Silva, Bruno; Saraiva, Margarida; Silva, Ana Sanches; Pastrana, Lorenzo; Carneiro, Olga Sousa; Cerqueira, Miguel A.Active food packaging is a dynamic area where the scientific community and industry have been trying to find new strategies to produce innovative packaging that is economically viable and compatible with conventional production processes. The materials used to develop active packaging can be organized into scavenging and emitting materials, and based on organic and inorganic materials. However, the incorporation of these materials in polymer-based flexible packaging is not always straightforward. The challenges to be faced are mainly related to active agents' sensitivity to high temperatures or difficulties in dispersing them in the high viscosity polymer matrix. This review provides an overview of methodologies and processes used in the production of active packaging, particularly for the production of active flexible films at the industrial level. The direct incorporation of active agents in polymer films is presented, focusing on the processing conditions and their effect on the active agent, and final application of the packaging material. Moreover, the incorporation of active agents by coating technologies and supercritical impregnation are presented. Finally, the use of carriers to help the incorporation of active agents and several methodologies is discussed. This review aims to guide academic and industrial researchers in the development of active flexible packaging, namely in the selection of the materials, methodologies, and process conditions.
- Avaliação do conhecimento de uma amostra da população portuguesa sobre o bisfenol APublication . Vilarinho, Fernanda; van der Kellen, Ana; Andrade, Mariana; Figueira, M Eduardo; Vaz, M Fátima; Silva, Ana SanchesO bisfenol A (BPA) é um composto orgânico, de origem industrial, com atividade estrogénica. A sua principal utilização encontra-se na produção de plásticos policarbonatos e resinas epóxi, aplicados a embalagens alimentares e produtos médicos. Devido aos perigos associados à ingestão repetida e a longo prazo deste xenoestrogénio, é importante avaliar a perceção e o conhecimento da população portuguesa acerca do BPA e dos seus efeitos para a saúde. Deste modo, foi elaborado um questionário sobre este composto e aplicado a uma amostra da população portuguesa. A amostra foi constituída por 249 indivíduos de diversas zonas do país, pertencentes a diversas faixas etárias e com vários níveis de escolaridade. O questionário compilou questões que permitem reunir dados socioeconómicos e obter informação acerca do conhecimento dos inquiridos sobre este composto químico. Os resultados obtidos mostram que 64% dos inquiridos nunca ouviram falar do BPA. Apesar de 92% dos inquiridos (dos que conheciam o BPA) terem conhecimento que a exposição a este químico produz efeitos negativos para a sua saúde, e que estes, estão maioritariamente associados à utilização de materiais plásticos em contacto com alimentos, 50% mostram desconhecimento de quais os tipos de riscos a que estão sujeitos. Concluiu-se que nesta amostra da população portuguesa o conhecimento sobre o bisfenol A (BPA) é escasso, e que a maioria dos inquiridos não conhece o composto.
- Determination of rhodamine and tetramethylrhodamine-5-maleimide by ultra high performance liquid chromatographyPublication . Silva, Ana Sanches; Vilarinho, Fernanda; Buonocore, GiovannaNanoscale materials present unquestionable advantages, however there is a need to understand how the nanoscale influences the toxicological properties of materials, as well as the possibility of exposure. Nowadays, we are still facing the lack of tools and methodologies available to easily track the movement and position of engineered nanomaterials (ENMs) from nanocomposites. Elemental analysis via atomic absorption spectrometry or inductively coupled plasma mass spectroscopy are the most commonly used techniques for tracking and detecting nanoclays. However, these methods lack the ability to track single or clustered nanoclay particles and their positions, which is an important feature. Recently fluorescent labeling has been proposed as a simple method to track particle at nanoscale. In this method fluorescent compound (tag) bonds covalently to the nanoclay allowing to track them. The main objective of this study was to develop an analytical method by Ultra High Performance Liquid Chromatographic (UHPLC) to determine simultaneously rhodamine and tetramethylrhodamine-5-maleimide, two potential labels of MMT. Due to the lack of information regarding the analytical behaviour of the selected fluorescent tags, there was the need of carrying out numerous tests to develop an UHPLC method that allowed determining the selected fluorescent tags. Different conditions of the methods were tested including chromatographic column, column temperature, mobile phase composition, mobile phase gradient and detectors conditions were tested. UHPLC was used because it allows reducing the time of analysis and to obtain well defined peaks and low quantification limits. Fluorescence detector and diode array detector (DAD) were compared as well as different solvents. The results of the calibration curves of rhodamine and tetramethylrhodamine-5-maleimide, prepared in ethanol and methanol, presented excellent determination coefficients in all cases, indicating suitability for quantification. Better response was obtained with fluorescence detector, allowing working at lower concentrations.
- Emerging Trends in Active Packaging for Food: A Six-Year ReviewPublication . Andrade, Mariana A.; Barbosa, Cássia H.; Ribeiro-Santos, Regiane; Tomé, Sidney; Fernando, Ana Luísa; Silva, Ana Sanches; Vilarinho, Fernanda; "The development of active food packaging has evolved rapidly in recent years, offering innovative solutions to enhance food preservation and safety while addressing sustainability challenges. This review compiles and analyzes recent advancements (2019–2024) in release-type active packaging, focusing on essential oils, natural extracts, and phenolic compounds as active agents. Primarily plant-derived, these compounds exhibit significant antioxidant and antimicrobial activities, extending shelf life and enhancing food quality. Technological strategies such as encapsulation and polymer blending have been increasingly adopted to overcome challenges related to volatility, solubility, and sensory impact. Integrating bio-based polymers, including chitosan, starch, and polylactic acid, further supports the development of environmentally friendly packaging systems. This review also highlights trends in compound-specific research, release mechanisms, and commercial applications, including a detailed analysis of patents and case studies across various food matrices. These developments have already been translated into practical applications, such as antimicrobial sachets for meat and essential oil-based pads for fresh produce. Moreover, by promoting the valorization of agro-industrial by-products and the use of biodegradable materials, emission-type active packaging contributes to the principles of the circular economy. This comprehensive overview underscores the potential of natural bioactive compounds in advancing sustainable and functional food packaging technologies.
- Exploring Cynara cardunculus L. by-products potential: Antioxidant and antimicrobial propertiesPublication . Barbosa, Cássia H.; Duarte, Maria Paula; Andrade, Mariana A.; Mateus, Ana Rita; Vilarinho, Fernanda; Fernando, Ana Luisa; Silva, Ana SanchesCynara cardunculus L. (cardoon), a perennial crop indigenous to the Mediterranean region, has gained recognition for its remarkable resilience to diverse weather conditions and its multifaceted applications across various industries, which includes the use of the flower as a vegetable rennet to produce some cheeses, as a source of biomass for energy, or its seed oil for human consumption, biodiesel, and animal feed. In some applications (e.g. biomass or seed production), when crop is harvested at the end of the growth cycle, the leaves remain as the main by-products, along with the flowers. In the context of a circular economy, the aim of this work was to undergone studies to determinate their biological properties (antioxidant and antimicrobial). Methanolic and ethanolic extracts of C. cardunculus L. (globe artichoke var. scolymus (L.) Fiori) and cultivated cardoon (var. altilis DC.)) leaves and flowers were characterised in terms of their polyphenol profile (total phenolic content (TPC), total flavonoid compounds (TFC), and ultra-high performance liquid chromatography coupled with time-of-flight mass spectrometry (UHPLC-ToF-MS)), antioxidant capacity (free radical DPPH inhibition system, β-carotene bleaching assay), and antimicrobial capacity (minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), antifungal). In addition, the cultivated cardoon leaves extracts were assessed before and after they were dried in an oven with forced air circulation to evaluate if this treatment affected their bioactive profile. Chlorogenic acid, apigenin, and luteolin were the most quantified of a total of sixteen compounds identified by UHPLC-ToF-MS. Cultivated cardoon dry leaf extract presented the best antioxidant capacity for both methanolic (EC50 = 0.8 mg/mL, antioxidant activity coefficient (AAC) = 279.67) and ethanolic (EC50 =2.1 mg/mL, AAC = 448.06) extracts, compared to the cardoon flower extracts and the globe artichoke leaf ex tracts. Dried cultivated cardoon leaf extracts presented higher antioxidant capacity than fresh cultivated cardoon leaf extracts, but a greater number of polyphenolic compounds were identified in fresh cultivated cardoon leaf extract. The Gram-positive bacteria were more sensitive to the activity of both ethanolic and methanolic extracts than the Gram-negative and cultivated cardoon dry leaf ethanolic extract presented lower MIC and MBC values (125–2000 µg/mL) for most of the tested microorganisms, thus showing higher antimicrobial activity. As for the cultivated cardoon leaf extracts, the dried leaf extracts exhibited better antimicrobial activity, with lower MIC values, than the fresh leaf extracts. The extracts only demonstrated a slight inhibition against the fungi Aspergillus fumigatus. In conclusion, studies performed indicate that dried leaves maintain their biological activities compared to fresh leaves, and that flowers present significant biological activity which suggests the great.
- Extending High Fatty Foods Shelf-Life Protecting from Lipid Oxidation and Microbiological Contamination: An Approach Using Active Packaging with Pomegranate ExtractPublication . Andrade, Mariana A.; Rodrigues, Pedro V.; Barros, Carolina; Cruz, Vasco; Machado, Ana Vera; Barbosa, Cássia H.; Coelho, Anabela; Furtado, Rosália; Correia, Cristina Belo; Saraiva, Margarida; Vilarinho, Fernanda; Ramos, Fernando; Silva, Ana SanchesThe search for new forms to extend foodstuffs’ shelf-life through the use of natural compounds and extracts continues to grow among researchers and the industry. In this line of thought, the main objective of this work was to develop, characterize and evaluate the effectiveness of an active food packaging based on polylactic acid (PLA) and incorporated with natural extracts obtained from grape and/or pomegranate by-products. In vitro, antioxidant methods were applied to evaluate the antioxidant capacity of three extracts: wort extract, freeze-dried pomegranate peels extract (PPE-FD), and natural pomegranate peels (PPE-N). Punicalagin (A + B) and ellagic acid were determined in PPE-FD, PPE-N, and active films by UHPLC-DAD. New PLA-based active packaging with PPE-FD (PLA/3PPE) and pomegranate peels (PLA/3PP) were developed, and their chemical, mechanical, and barrier properties were evaluated. Moreover, the effectiveness of the new film was carried out through the study of lipid oxidation state and microbial contamination of two high-fat content foodstuffs, almonds and beef meat. PPE-FD presented high antioxidant capacity and high content in total phenolics and flavonoid compounds. The PLA/3PPE and PLA/3PP prevented the lipid oxidation of meat and presented antimicrobial activity against Staphylococcus aureus. The addition of the PPE-FD and the pomegranate peels to the PLA did not affect the morphology of the polymer. Although both PPE-FD and pomegranate peels presented punicalagin (A + B) and ellagic acid, only ellagic acid was identified and quantified in the active PLA. Active PLA films were not effective in delaying the lipid oxidation of almonds, but they showed to be significantly effective in delaying the lipid oxidation of beef meat and reducing the microbial growth in this food matrix over time.
- Extension of Poultry Meat Shelf Life Using Cynara cardunculus L. Leaf Extracts as a Natural PreservativePublication . Barbosa, Cássia H.; Andrade, Mariana A.; Vilarinho, Fernanda; Silva, Ana Sanches; Fernando, Ana Luísa;Food additives are used to prevent food spoilage and extend its shelf life. However, con cerns regarding the potential health implications associated with some synthetic additives have prompted research efforts aimed at identifying natural alternatives, such as plant extracts. Cynara cardunculus L. (cardoon) is known for its antimicrobial and antioxidant properties. The aim of this study was to evaluate the capability of ethanolic food-grade extracts from cultivated cardoon and globe artichoke leaves to preserve poultry breast meat during refrigerated storage. A total of seven treatment groups were tested: one control group (no extract) and six active groups with 0.5%, 1%, and 2% (w/w) of either cultivated cardoon or globe artichoke leaf extracts. Lipid oxidation, moisture, colour, pH, acidity, and microbial growth were assessed in poultry meat samples over 15 days. Both extracts were effective in extending shelf life, up to 11 days, by delaying lipid oxidation and microbial growth. Cardoon extract (1% w/w) displayed superior antimicrobial efficacy, maintaining microbial counts below 5 Log CFU/g meat until day 15, compared to the control. Culti vated cardoon leaf extract proves promising as a natural antimicrobial and antioxidant, extending the shelf life of poultry meat. This presents an opportunity to maintain the quality of meat products, aligning with consumer preferences for natural ingredients and sustainable practices.
- Fluorescein 5-maleimide: label of food contact nanocompositesPublication . Silva, Ana Sanches; Vilarinho, Fernanda; Buonocore, GiovannaEngineered nanomaterials (ENMs) are increasingly being used due to their physical and chemical properties that allow improving a wide range of consumer products. Although they present a vast number of benefits, they also present risks to human health and the environment. Therefore, there is the need of evaluating the risks of nanotechnologies in foods. To fulfill this require new techniques are being developed. Fluorescent labeling is a simple approach for particle tracking that presents low detection limits. A fluorescent organic dye can be directly incorporated into layered silicates like montmorillonite (MMT) by ionic exchange but this can be dislodged from the substrate during the extrusion process. However the covalent bond of the fluorescent tag to the nanoclay can be a good alternative because it provides stability between the fluorescent tag and the clay. The main objective of this study was to develop an analytical method by Ultra High Performance Liquid Chromatographic (UHPLC) to determine fluorescein 5-maleimide, a fluorescent compound, as potential label of MMT. Conditions like chromatographic column, column temperature, mobile phase composition, mobile phase gradient as well as detector conditions were tested. Fluorescence detector and diode array detector (DAD) were compared. In general good linearity was found, excellent determination coefficients were achieved in all cases. Regarding the response of both detectors, as expected, better response was also obtained with fluorescence detector, allowing obtaining lower limits of quantification. The quantification limits of fluorescein 5-maleimide with the fluorescence detector were, at least, 10 times lower than with the DAD detector. Different behaviour was found in the two solvents tested. Ethanolic solutions allowed obtaining lower detection limits (LOD) than methanolic solutions (LOD ethanol = 0.03 µg/mL; LOD methanol =0.06 µg/mL, using fluorescence detector).
- Industrial fruits by-products and their application in active food packagingPublication . Andrade, Mariana; Lima, Vasco; Silva, Ana Sanches; Vilarinho, Fernanda; Castilho, Maria Conceição; Khwaldia, Khaoula; Ramos, FernandoFood Packaging: Main functions (Protection; Increase shelf-life; Maintain organoleptic properties); Non-biodegradable materials.
- Materials reinforced with nanocellulose: promising nanocomposites for food packaging?Publication . Vilarinho, Fernanda; Vaz, M. Fátima; Silva, Ana SanchesThe development of new packaging materials offering new functionalities and lower environmental impact, is now an urgent need. On one hand, the shelf life extension of packaged products can be an answer to the exponential increase of worldwide demand for food. On the other hand, the increase in the price of crude oil, together with the uncertainty related to its durability, has imposed the necessity to manufacture new structures to replace oil-derived polymers in the future. Finally, consumers' awareness towards environmental issues increasingly pushes industries to look with renewed interest to “green” solutions. Thus, in the last years’ numerous polymers have been exploited to develop biodegradable food packaging materials. The usage of biopolymers has been limited due to the poor mechanical and barrier properties. These properties can be enhanced by adding reinforcing nano-sized compounds to form nanocomposites. Cellulose is probably the most used and well-known renewable and sustainable raw material. The mechanical properties, reinforcing capabilities, abundance, low density and biodegradability of the cellulose nanoparticles make them ideal candidates for the processing of polymer nanocomposites. The present review focuses on the combination of nanocellulose with polymers such as wheat gluten; starch, gelatine; agar; polyvinyl alcohol (PVA); chitosan. The methods of processing, level of incorporation and the enhanced material properties are discussed. Future trends are addressed namely regarding regulations and food industry applications.