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Percorrer por autor "Vedor, Rita"

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  • Achieving efficient viability of akkermansia muciniphila during aerobic storage and gastrointestinal passage through calcium-alginate encapsulation
    Publication . Machado, Daniela; Fonseca, Mariana; Vedor, Rita; Barbosa, Joana Cristina; Gomes, Ana Maria
    2023-09Documento de conferência Acesso aberto Ver mais
  • Advancing circular nutrition: the development of a freeze-dried snack based on broccoli stalk powder
    Publication . Soares, Inês; Machado, Daniela; Vedor, Rita; Sousa, Sérgio; Orvalho, Telma; Dias, Sara; Alves, Marco; Gomes, Ana Maria
    Aim: The upcycling of agri-food by-products presents a sustainable strategy for reducing waste and creating value-added products. This study aimed to develop a freeze-dried snack incorporating broccoli stalks, an often discarded by-product, and to characterise its nutritional composition, microbiological quality, physicochemical properties and bioactive potential. Method: Broccoli stalks were freeze-dried, milled into a powder, and incorporated into a snack formulation that was subsequently lyophilised. Nutritional profile (moisture, total protein, total fats, ash, total carbohydrates and dietary fibre) was determined using AOAC methods. Microbiological quality was assessed by enumerating mesophiles in Plate Count Agar, yeasts and molds in Potato Dextrose Agar, and enterobacteria in Violet Red Bile Glucose Agar. Physicochemical properties (pH, water activity, texture and colour) were analysed over 4-months of storage. Bioactive potential was evaluated by quantifying total phenolic content (using Folin–Ciocalteu method) and measuring antioxidant activity (via ABTS assay) and antidiabetic activity (through ?-glucosidase inhibition assay). Results: The developed snack demonstrated high dietary fibre content (33.73 g/100 g) and substantially high protein levels (24.30 g/100 g). Microbial loads remained below 10? CFU/g, indicating adequate microbiological safety. Over four months of storage, a gradual decrease in pH was observed (from 6.39 to 5.90), accompanied by an increase in water activity (from 0.21 to 0.32). Texture analysis indicated an increase in both hardness (from 11.33 kg to 14.72 kg) and crispiness (from 43.75 kg·s to 45.54 kg·s), measured by texturometer (Texture Profile Analysis). Despite the slight increase in water activity, the product became firmer and crunchier over time. The reported colour variations (0 vs. 4 months) — ?E of 15.20 on the exterior and 14.42 on the interior — were not sufficient to significantly affect the product's visual appeal. Furthermore, the snack exhibited notable total phenolic content (2.121 mg gallic acid equivalents/g), along with substantial antioxidant (6.088 ?mol Trolox equivalents/g) and antidiabetic activity (73.95% ?-glucosidase inhibition). Conclusion: The lyophilised snack developed from broccoli stalks demonstrated a favourable nutritional profile, with adequate microbiological quality and promising antioxidant and antidiabetic properties. These findings support the incorporation of vegetable by-products in the formulation of sustainable, functional foods aligned with circular economy principles.
    2025-11-01Documento de conferência Acesso aberto Ver mais
  • Akkermansia muciniphila encapsulated in calcium-alginate hydrogelated matrix: viability and stability over aerobic storage and simulated gastrointestinal conditions
    Publication . Machado, Daniela; Fonseca, Mariana; Vedor, Rita; Sousa, Sérgio; Barbosa, Joana Cristina; Gomes, Ana Maria
    Akkermansia muciniphila is considered a next-generation probiotic to be incorporated in new food and pharmaceutical formulations. Effective delivery systems are required to ensure high probiotic viability and stability during product manufacture, shelf-life, and post-consumption, namely, throughout digestion. Hydrogelated matrices have demonstrated promising potential in this dominion. Hence, this work aimed to evaluate the effect of a calcium-alginate hydrogelated matrix on A. muciniphila viability during 28-days refrigerated aerobic storage and when exposed to simulated gastrointestinal conditions, in comparison with that of free cells. Akkermansia muciniphila was successfully encapsulated in the calcium-alginate matrix via extrusion (60% encapsulation yield). Furthermore, encapsulated A. muciniphila exhibited high stability (a loss in viability lower than 0.2 log-cycle) after 28-days of refrigerated aerobic storage, maintaining its viability around 108 CFU/g. Prominently, as the storage time increased, encapsulated A. muciniphila revealed higher viability and stability regarding in vitro gastrointestinal conditions than free cells. This suggests that this encapsulation method may attenuate the detrimental effects of prolonged aerobic storage with a subsequent gastrointestinal passage. In conclusion, encapsulation via extrusion using a calciumalginate hydrogelated matrix seems to be a promising and adequate strategy for safeguarding A. muciniphila from adverse conditions encountered during refrigerated aerobic storage and when exposed to the gastrointestinal passage.
    2023-11-01Artigo científico Acesso aberto Ver mais
  • Avaliação do potencial prebiótico das “farinhas” de batata-doce e bagaço de pêra
    Publication . Soares, Inês; Vedor, Rita; Fonseca, Mariana; Pinto, Jorge; Machado, Daniela; Gomes, Ana Maria
    O desperdício alimentar, uma forma de biowaste comum a nível global, é um dos maiores desafios de sustentabilidade que a indústria alimentar enfrenta. A indústria de frutas e hortícolas destaca-se neste contexto, sendo responsável por 25 a 30% do total, incluindo resíduos como cascas, sementes e bagaço [1,2]. A valorização deste tipo de resíduos constitui uma estratégia que visa transformar estes em produtos de valor acrescentado. Concretamente, as farinhas de bagaço de pêra e de batata-doce mantêm altos níveis de nutrientes e compostos bioativos, criando oportunidades para o desenvolvimento de alimentos funcionais promotores de saúde e bem-estar [3,4]. Este estudo visou investigar o potencial prebiótico destas farinhas, avaliando a sua capacidade de estimular o crescimento e a atividade metabólica de duas estirpes probióticas, nomeadamente Lacticaseibacillus rhamnosus GG (LGG) e Bifidobacterium longum subsp. infantis DSM 20088 (B.infantis). A seleção destas estirpes deve-se às suas reconhecidas propriedades benéficas para a saúde intestinal e à capacidade de fermentar diferentes tipos de substratos. A metodologia utilizou o meio Man-Rogosa- Sharpe (MRS) como base, com modificações para criar diferentes condições de cultivo, nomeadamente: um controlo negativo (MRS sem glucose), um controlo positivo (MRS com 2% de glucose), um controlo prebiótico (MRS com 2% de frutooligossacarídeos) e meios com 2% e 6% de farinhas de batata-doce e de bagaço de pêra. A LGG foi cultivada em condições aeróbicas, enquanto a B. infantis manteve- se em anaerobiose, ambas a 37ºC. As amostras foram colhidas às 0, 3, 6, 10 e 24 horas de incubação para quantificação de unidades formadoras de colónias (UFC) e medição do pH, avaliando o crescimento e metabolismo bacteriano, respetivamente. Os resultados demonstraram que, no geral, a farinha de bagaço de pêra a 6% e a farinha de batata-doce, nas concentrações de 2 e 6%, promoveram o crescimento de B. infantis de forma equivalente ou ligeiramente superior à glucose (entre 3 a 6 x 10 9 UFC/mL). Por outro lado, as concentrações mais elevadas (6%) de farinha de batata- doce e de bagaço de pêra favoreceram o crescimento de L. rhamnosus GG de forma mais significativa do que a glucose (+ 0.5 ciclo log). A sua elevada capacidade de estimular o crescimento e o metabolismo de bactérias probióticas revela um potencial prebiótico para estas farinhas e destaca a sua aplicação como potenciais ingredientes funcionais para o desenvolvimento de produtos alimentares sustentáveis, com valor acrescentado e potencial benefício para a saúde humana.
    2024-11Documento de conferência Acesso aberto Ver mais
  • Can a functional cheese spread incorporating Akkermansia muciniphila deliver beneficial physicochemical and biological properties while enhancing probiotic stability and viability during aerobic storage and in vitro digestion?
    Publication . Fonseca, Mariana; Vedor, Rita; Barbosa, Joana C.; Gomes, Ana Maria; Machado, Daniela
    In the present study, next generation probiotic Akkermansia muciniphila was incorporated into a dairy matrix containing Portuguese whey cheese and Greek-style yoghurt in a proportion of 3.5:1, respectively. Subsequently, this innovative food was characterized in terms of microbiological and physicochemical parameters, total phenolic content and antioxidant, antidiabetic, and antihypertensive activities, as well as its protective effect on A. muciniphila viability during 21 d of refrigerated aerobic storage and when subjected to simulated gastrointestinal passage. The probiotic cheese spread displayed high microbiological quality, low total phenolic content (0.36 mg gallic acid equivalents/g of dried cheese) and interesting biological activities, including antidiabetic (98.10% α-glucosidase inhibition) and antihypertensive (49.18% angiotensin converting enzyme inhibition). Simultaneously, this food ensured a high A. muciniphila viability (>108 CFU/g) during 21 d of refrigerated aerobic storage with subsequent in vitro digestion. Additionally, this probiotic cheese presented a similar profile in terms of texture, color, water activity and pH when compared to the cheese control (without A. muciniphila), suggesting a potentially high acceptance among consumers. In conclusion, the developed cheese spread seems to be a promising and suitable food vector to safeguard A. muciniphila viability during refrigerated aerobic storage for at least 21 d with subsequent gastrointestinal passage.
    2024-05-08Artigo científico Acesso aberto Ver mais
  • Chocolate funcional contendo o probiótico Bifidobacterium animalis subespécie lactis BB-12
    Publication . Vedor, Rita; Machado, Daniela; Barbosa, Joana C.; Gomes, Ana Maria
    O chocolate é um dos produtos alimentares mais atrativos para a população e tem sido proposto como um bom vetor para a libertação de probióticos, conhecidos como microrganismos vivos que, quando administrados em quantidades adequadas, conferem benefícios à saúde humana 1,2. Especificamente, a bactéria probiótica Bifidobacterium animalis subespécie lactis BB-12®, originária de uma coleção de culturas lácteas (Chr. Hansen), tem sido associada a efeitos benéficos a nível gastrointestinal e da função imunológica [3]. No presente trabalho, a estirpe probiótica B. animalis subespécie lactis BB-12® foi incorporada em chocolates com três diferentes teores de cacau (33.6%; 54.5% e 70.5%), sendo avaliada a viabilidade ao longo do armazenamento aeróbio a temperatura ambiente (25ºC) por 28 dias. Além disso, cada chocolate incorporando o probiótico foi caracterizado em termos de pH, conteúdo de compostos fenólicos e atividade antioxidante, usando chocolates controlo (sem bactéria) para fins comparativos. Os nossos resultados mostraram que B. animalis subespécie lactis BB-12® incorporada no chocolate com teor de cacau 70.5% apresentou maior viabilidade ao longo do armazenamento. De facto, a viabilidade do probiótico foi mantida em torno de 108 UFC/g, sendo este valor superior ao limite estabelecido de 106 – 107 UFC/g para que um produto probiótico exerça efeitos benéficos. Através da medição de pH, verificou-se que a adição do probiótico não altera os valores em comparação com os chocolates controlo (sem bactéria) e que durante o armazenamento também não existiram oscilações consideráveis, sugerindo que as bactérias se encontram metabolicamente inativas, o que poderá estar relacionado com a manutenção da sua viabilidade ao longo do tempo. Relativamente às análises do conteúdo de compostos fenólicos, verificou-se um aumento de compostos totais com o aumento do teor de cacau na matriz alimentar, embora a adição da bactéria probiótica não interfira com o conteúdo total. Além disso, através da medição da atividade antioxidante observou-se uma tendência crescente com o aumento de teor de cacau. Em conclusão, o nosso estudo mostrou que o chocolate negro, mais especificamente com teor de cacau de 70.5%, pode ser considerado uma potencial e valiosa matriz alimentar veiculando o probiótico B. animalis subespécie lactis BB-12®. Além disso, esta matriz é uma importante fonte de compostos bioativos, nomeadamente compostos fenólicos, que possuem atividade antioxidante comprovada.
    2022-10-17Documento de conferência Acesso aberto Ver mais
  • Development and characterization of a cheese spread incorporating the next generation probiotic akkermansia muciniphila
    Publication . Fonseca, Mariana; Vedor, Rita; Machado, Daniela; Barbosa, Joana; Gomes, Ana
    2023-11-23Documento de conferência Acesso aberto Ver mais
  • Development of a new beetroot snack: impact of pulsed electric fields (PEF) pretreatment on the physicochemical and bioactive properties
    Publication . Orvalho, Telma; Dias, Sara; Machado, Daniela; Soares, Inês; Vedor, Rita; Gomes, Ana; Alves, Marco
    Introduction: Low-caliber vegetables are used to produce juices, flours and dried snacks. The valorization of non-marketable products through the development of new high value-added food products is aligned with current trends and contributes for a more sustainable and circular food sector. PEF is an emerging and promising technology with the potential to reduce freeze-drying time and improve the quality characteristics of processed fruit and vegetables. Objectives: This study evaluated the impact of PEF pretreatment on the physicochemical and bioactive properties of a freeze-dried snack made from low-caliber beetroot.
    2025-04-02Póster não publicado nas atas da conferência Acesso aberto Ver mais
  • Development of functional chocolate incorporating Akkermansia muciniphila: the role of cacao powder
    Publication . Vedor, Rita; Machado, Daniela; Barbosa, Joana; Andrade, José C.; Gomes, Ana M.
    Objective: This study evaluated the feasibility of using chocolate as a food matrix for delivering Akkermansia muciniphila, a next- generation probiotic known for improving gut barrier function and metabolic health. The research assessed the viability of A. muciniphila in three different chocolate formulations, characterised the chocolate’s biological characteristics, and evaluated the potential prebiotic and biological activities of cocoa powder. Methods: The viability and stability of A. muciniphila DSM 22959 in three chocolate matrices (33.6%, 54.5% and 70.5% w/w cocoa) were evaluated over 28 days of aerobic storage. Total phenolic content was measured (Folin-Ciocalteu assay), and antioxidant (ABTS) and antidiabetic properties were assessed. Cocoa powders samples (30%, 90% and 100%) were also evaluated for antioxidant and antidiabetic properties, as well as prebiotic potential for supporting A. muciniphila (via viable cell counts) and acidification through pH monitoring and HPLC analysis of organic acids. Results: Chocolate containing 54.5% (w/w) cocoa emerged as the most suitable matrix for preserving A. muciniphila viability (above 106 CFU/g) during storage. The 70.5% (w/w) cocoa chocolate exhibited higher levels of total phenolic compounds, as along with good antioxidant (349916.87 ?mol of Trolox equivalent per g of sample) and antidiabetic (100%) properties. Cocoa powders with 90% and 100% (w/w) cocoa not only showed elevated phenolic content and antioxidant activity but also promoted A. muciniphila growth, as evidenced by a decrease in pH and increased production of short-chain fatty acids after 48 hours of fermentation. Conclusions: Chocolate matrixes demonstrated to have favourable biological characteristics acting as a suitable vector for A. muciniphila DSM 22959.
    2025-09-16Documento de conferência Acesso aberto Ver mais
  • Effects of conventional hot air dehydration and lyophilization on the total phenolic content and antioxidant potential of broccoli stalk powders
    Publication . Machado, Daniela; Soares, Inês; Vedor, Rita; Orvalho, Telma; Alves, Marco; Gomes, Ana Maria
    Introduction: The valorization of agro-industrial byproducts plays a key role in promoting sustainability and supporting the development of functional foods (Food and Agriculture Organization of the United Nations, 2019; Ramírez- Pulido et al., 2021). Broccoli stalks, often industrially discarded, are a rich source of bioactive substances, particularly phenolics, with potential health- promoting effects (Yan et al., 2023). Efficient drying methods can transform these byproducts into high-value ingredients, while preserving their bioactive potential (Ramírez-Pulido et al., 2021). Objectives: Evaluate the impact of two drying methods (conventional hot air dehydration and lyophilization) on the total phenolic content and antioxidant activity of broccoli stalk powders. Conclusions: This work reinforces the potential of broccoli stalks as sources of bioactive substances, especially phenolic compounds. Both drying methods enabled the preservation of bioactive content, fostering the development of functional ingredients and supporting circular economy practices through food waste reduction and sustainable byproduct utilization.
    2025-07Póster não publicado nas atas da conferência Acesso aberto Ver mais