Browsing by Author "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.
- 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.
- 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.
- Extending beef meat shelf life: an approach using active food packaging with pomegranate extract and peelsPublication . 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, AnaMore than 50% of the pomegranate fruit (Punica granatum L.) is not considered edible, being composed by peels (50%) and seeds (10%). Pomegranate peels represent an excellent source of bioactive compounds with excellent antioxidant and antimicrobial activities due to the peels’ high content in phenolic compounds, specially punicalagin (A+B) and ellagic acid. The aim of the present study was to evaluate the potential effects of a polylactic acid (PLA) based active packaging incorporated with pomegranate peels and an ethanolic extract from pomegranate peels in the shelf-life extension of fresh meat. Two PLA-based active packaging incorporating 3% (w/w) of pomegranate peels (PLA/3PP) and 3% (w/w) of pomegranate peels extract (PLA/3PPE) were used to pack beef meat. The samples were stored at 4 °C, for a maximum of 11 days. The meats’ lipid oxidation and microbial contamination was evaluated at the end of 1, 4, 6, 8 and 11 storage days. Lipid oxidation was measured by the Thiobarbituric Acid Reactive Substances assay (TBARS)[1]. Meat’s total microorganisms count at 30 °C was performed using the automated method TEMPO® Aerobic Count- AFNOR BIO 12/35–05/13. Both PLA active packaging significantly delayed meat’s lipid oxidation and microbial growth. The meat with PLA/3PP and PLA/3PPE presented a difference up to 3 log CFU/g on the 11th storage day. Even though both active packaging were able to inhibit meat’s lipid oxidation, these results showed that PLA/3PP was more efficient, providing insights for the use of this bio-waste towards environmental sustainability.
- Extending poultry meat shelf life through the application of Cyanara cardunculus L. leaf extractsPublication . Barbosa, Cássia; Andrade, Mariana; Vilarinho, Fernanda; Sanches Silva, Ana; Fernando, Ana LuisaCynara 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.
- Hypotensive effects of genistein: from chemistry to medicinePublication . Sureda, Antoni; Sanches Silva, Ana; Sánchez-Machado, Dalia Isabel; López-Cervantes, Jaime; Daglia, Maria; Nabavi, Seyed Fazel; Nabavi, Seyed MohammadGenistein (4', 5, 7-trihydroxyisoflavone), a naturally occurring flavonoid characteristic of Leguminoseae plants, is a phyto-oestrogen exerting oestrogenic activity as both an agonist and an antagonist substance. A large body of evidence suggests that genistein possesses many physiological and pharmacological properties that make this molecule a potential agent for the prevention and treatment of a number of chronic diseases. Growing evidence suggests that genistein could act as a vasodilating, anti-thrombotic, and anti-atherosclerotic agent, exerting these effects through different mechanisms of action. This paper aims to review data from the literature assessing the beneficial effects of genistein on hypertension, one of the most important cardiovascular disease risk factors along with hyperglycemia and hyperlidipemia. In addition, we discuss the chemistry, main sources and bioavailability of genistein. Scientific findings support genistein's potential as a promising anti-hypertensive agent in different experimental models. However, clinical trials are very limited and more research will be required before genistein intake can be recommended as part of therapies targeting raised blood pressure.
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