Percorrer por autor "Sanches Silva, Ana"
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- Antioxidant and antimicrobial properties of PLA based active packaging with pomegranate peels and extractPublication . Andrade, Mariana; Rodrigues, Pedro; Barros, Carolina; Cruz, Vasco; Machado, Ana; Barbosa, Cássia; Coelho, Anabela; Furtado, Rosália; Correia, Cristina; Saraiva, Margarida; Vilarinho, Fernanda; Ramos, Fernando; Sanches Silva, AnaActive food packaging’ primary goal is to extend foodstuffs’ shelf life, through a dynamic and continuous interaction between the package and the packaged food. In an emission active packaging, the objective is the gradual release of antioxidant and/or antimicrobial compounds into the food surface, to delay the natural foods’ degradation. The active compounds can be extracted from several sources, such as aromatic plants, seaweeds, fruits by-products, among others. Since 50% of pomegranate is composed by peels, and since it is mainly consumed in juice and jam form, pomegranate peels may represent a considerable asset for the extraction of such compounds. The principal objective of this work was to evaluate the antioxidant and antimicrobial properties of polylactic-based active packaging incorporated with 3% (w/w) of pomegranate peels (PLA/3PP) and 3% (w/w) of pomegranate peels extract (PLA/3PPE). For the in vitro antioxidant activity evaluation, 9.08 cm2 of films were immersed in the food simulator, ethanol 95% (v/v), at 40 °C for 10 days. Then, the DPPH radical scavenging assay was performed, as well as the total content of phenolic compounds, total content in flavonoids, content in punicalagin (A+B) and ellagic acid were determined. Also, to fully determine the total content in punicalagin (A+B) and ellagic acid, the films were kept in methanol at 25 and 40 °C for 24 h. The antimicrobial activity of the films was evaluated with Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis, and Escherichia coli, in accordance with ISO 22196:2011. Results showed that PLA/3PPE presented a higher antioxidant potential and higher content in phenolic compounds and flavonoids. Only ellagic acid was detected in the active PLA-based films. Regarding the antimicrobial activity, both films presented antimicrobial activity against S. aureus.
- Applying Cynara cardunculus L. leaf extracts to increase poultry meat shelf lifePublication . Barbosa, Cássia; Andrade, Mariana; Vilarinho, Fernanda; Sanches Silva, Ana; Fernando, Ana LuisaCardoon, 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.
- Biodegradable whey protein films with cardoon extract as natural alternatives to natamycin in cheese preservationPublication . Barbosa, Cássia H.; Andrade, Mariana A.; Vilarinho, Fernanda; Sanches Silva, Ana; Fernando, Ana LuísaNowadays, consumers demand more natural foods with fewer synthetic additives, which drives research into biodegradable active packaging enriched with plant extracts, essential oils, or agro-industrial by-products rich in bioactive compounds. Cardoon (Cynara cardunculus L.) is a multipurpose crop whose flower is traditionally used in cheesemaking, while its leaves, a major by-product, are rich in antimicrobial and antioxidant compounds. Whey, another by-product of the cheese industry, can be used to produce biodegradable films and coatings, whose functionality can be enhanced by incorporating natural extracts. In cheesemaking, natamycin is widely applied to prevent fungal growth, but concerns over its excessive use highlight the need for safer, natural alternatives. This study aimed to evaluate the potential of whey protein-based films incorporated with cardoon leaf extract (0.5, 1.0, and 2.0 % w/v) to extend the shelf life of cheese in order to understand if it can be a substitute to natamycin. Cheeses were wrapped in the active films and stored at 5 ± 2 °C for 30 days. Samples were analysed for microbial growth, physicochemical parameters (moisture, pH, titratable acidity), and lipid oxidation. Results indicate that active films, particularly the whey protein film with 2.0 % cardoon extract, were effective in delaying microbial development in both rind and interior, presenting the lowest counts of total viable microorganisms (6.77 ± 0.52 Log CFU/g), moulds and yeasts (5.38 ± 0.12 Log CFU/g), and Enterobacteriaceae (4.26 ± 0.10 Log CFU/g) compared to control samples (untreated and without extract). The films also helped retain rind moisture and limited titratable acidity increases, indicating delayed microbial metabolism. Lipid oxidation remained at low levels, with films containing 2.0 % cardoon extract showing the strongest antioxidant effect. Overall, the incorporation of cardoon-based extracts into whey protein films demonstrated antimicrobial and antioxidant properties, contributing to improved cheese preservation during refrigerated storage. This sustainable approach reduces reliance on synthetic preservatives while valorising agro-industrial by-products.
- Cardoon leaves as a nutrient food source: promoting sustainability and circular economyPublication . Barbosa, Cássia H.; Andrade, Mariana A.; Tomé, Sidney; Vilarinho, Fernanda; Fernando, Ana Luísa; Sanches Silva, AnaAgro-industrial by-products are a substantial source of bioactive compounds and nutrients. The valorisation of these by-products has the potential to promote environmental sustainability and a circular economy. This practice can lead to a significant advancement in sustainable food production. Cardoon (Cynara cardunculus L.) is a multipurpose crop, and its flowers are used as a natural coagulant in the cheesemaking process in countries such as Portugal and Spain. Cardoon leaves are rich in bioactive compounds, yet they are still often discarded as waste. These leaves can be directly consumed or used as an active ingredient in food packaging, thereby promoting resource efficiency and waste reduction. This study aims to evaluate the nutritional composition of cardoon leaves and their potential as a food ingredient. Fresh cardoon leaves were analyzed according to their content of moisture, ash, total protein, total fat, total dietary fiber, and total sugars, as well as their fatty acid profile. The results, expressed based on the weight of the fresh product, show that cardoon leaves contain 2.4 g/100 g, indicating a rich mineral composition. The total fat content is low, at 0.2 g/100 g, with only 0.05 g/100 g of saturated fat. The protein content (4.2 g/100 g) is considered adequate, highlighting its potential as a plant-based protein source. Additionally, the high fiber content (7.9 g/100 g) supports digestive health, while the low sugar content (0.9 g/100 g) further enhances its nutritional profile. Although cardoon leaves are often considered waste products, they offer substantial nutritional value, boasting high levels of protein, fiber, and minerals, as well as low levels of sugar and fat. Their effective valorisation can create a more sustainable system of food production. By incorporating cardoon leaves into the human diet and food packaging, their full potential can be achieved while minimizing waste and promoting sustainable consumption.
- Citrus By-Products: Valuable Source of Bioactive Compounds for Food ApplicationsPublication . Andrade, Mariana A.; Barbosa, Cássia; Shah, Muhammad Ajmal; Ahmad, Nazir; Vilarinho, Fernanda; Khwaldia, Khaoula; Sanches Silva, Ana; Ramos, FernandoCitrus production produces about 15 million tons of by-products/waste worldwide every year. Due to their high content of bioactive compounds, several extraction techniques can be applied to obtain extracts rich in valuable compounds and further application into food applications. Distillation and solvent extraction continues to be the most used and applied extraction techniques, followed by newer techniques such as microwave-assisted extraction and pulsed electric field extraction. Although the composition of these extracts and essential oils directly depends on the edaphoclimatic conditions to which the fruit/plant was exposed, the main active compounds are D-limonene, carotenoids, and carbohydrates. Pectin, one of the most abundant carbohydrates present in Citrus peels, can be used as a biodegradable polymer to develop new food packaging, and the extracted bioactive compounds can be easily added directly or indirectly to foods to increase their shelf-life. One of the applications is their incorporation in active food packaging for microbiological and/or oxidation inhibition, prolonging foods’ shelf-life and, consequently, contributing to reducing food spoilage. This review highlights some of the most used and effective extraction techniques and the application of the obtained essential oils and extracts directly or indirectly (through active packaging) to foods.
- Cyanara cardunculus L. by-products as a sustainable source of bioactive compounds for industrial applicationsPublication . Barbosa, Cássia H.; Andrade, Mariana A.; Duarte, Maria Paula; Mateus, Ana Rita; Vilarinho, Fernanda; Fernando, Ana Luísa; Sanches Silva, AnaCynara cardunculus L. (cardoon) is a versatile perennial crop that thrives in challenging environments with high productivity. Its flowers are valued for their coagulating properties in cheesemaking, while its leaves, rich in bioactive compounds, are normally discarded. This study aimed to assess the antioxidant and antimicrobial potential of ethanolic and methanolic extracts from fresh and dried cultivated cardoon var. altilis DC leaves (FCC and DCC, respectively) to evaluate the impact of oven-drying with forced air circulation on the bioactive profile of the leaves. Dried cultivated cardoon leaf extracts exhibited stronger antioxidant activity than fresh leaf extracts, although fresh leaves contained a greater variety of polyphenolic compounds. Among the 16 identified compounds, chlorogenic acid, apigenin, and luteolin were the most abundant. The best antioxidant activity was observed in dried leaf extracts for both methanolic (EC50 = 0.8 mg/mL, AAC = 279.67) and ethanolic (EC50 = 2.1 mg/mL, AAC = 448.06) solvents. Regarding antimicrobial properties, Gram-positive bacteria showed higher sensitivity to both ethanolic and methanolic extracts compared to Gram-negative bacteria. The dried leaf ethanolic extract demonstrated stronger antimicrobial activity, with lower minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values (125–2000 μg/mL) across most tested microorganisms. Dried leaf extracts exhibited better antimicrobial efficacy than fresh leaf extracts, although only mild inhibition was observed against Aspergillus fumigatus. In conclusion, the findings suggest that dried cardoon leaves are a valuable by-product as a source of bioactive compounds for various industrial applications, particularly in the food industry, as well as in cosmetic and pharmaceutical industries. In this sense, the use of active compounds obtained from cardoon leaves is aligned with the concepts of circular economy and sustainability. More specifically, it is aligned with the United Nations Sustainable Development Goal 12, Ensure sustainable consumption and production patterns. This approach promotes both environmental and economic sustainability by transforming high-value by-products into innovative applications.
- Effect of pomegranate peels and extract in barrier, optical and mechanical properties of polylactic acid-based active packagingPublication . Andrade, Mariana; Vilarinho, Fernanda; Rodrigues, Pedro; Barros, Carolina; Cruz, Vasco; Machado, Ana Vera; Barbosa, Cássia; Ramos, Fernando; Sanches Silva, AnaBeing more than 50 % of pomegranate (Punica granatum L.) constituted by non-edible parts, namely peels (50%) and seeds (10%), pomegranate is an excellent source of by-products. Its peels and seeds present excellent antioxidant and antimicrobial activities and a high content of phenolic compounds, namely ellagitannins. This work aimed to evaluate the mechanical and optical properties of two polylactic acid (PLA)-based active packaging with 3 wt.% pomegranate peels (3PP) or 3 wt.% pomegranate peel extract (3PPE). All the samples were produced on a laboratory scale with techniques and processing conditions used in industry. The production of packaging with flexible films is mainly carried out by tubular film extrusion. With this processing method it is possible to produce samples with molecular orientation and reduced thickness equal to that of the packages currently on the market. The structural and morphological characterization of the films were evaluated by FTIR and SEM, and the color by UV-vis. Water vapor transmission and mechanical properties were also measured. The color was measured by Shimadzu UV2401PC reflectance spectrophotometer. Water vapor transmission, oxygen permeability and mechanical properties were also measured. The FTIR and SEM results indicate the incorporation of the pomegranate peels and peels extract in the PLA matrix, where PLA/3PPE showed better particle homogenization than the PLA/3PP. Regarding the color variations, the PLA/3PPE presented higher variations in terms of L*, a*, and b*. The incorporation of pomegranate derivates has a negative effect on the tensile strength and Young modulus, but a significant increase of the elongation at break for PLA/3PPE. The PLA film's water vapor barrier properties do not suffer any alteration with the incorporation of pomegranate extract.
- Embalagens Alimentares: riscos e sua avaliaçãoPublication . Sanches Silva, Ana
- Embalagens e sua Interacção com os AlimentosPublication . Sanches Silva, Ana
- Exploring Cyanara cardunculus L. potential for the food industry: the antioxidant patternPublication . Barbosa, Cássia; Andrade, Mariana; Vilarinho, Fernanda; Fernando, Ana Luisa; Sanches Silva, AnaCynara 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.
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