Percorrer por autor "Gomes, Ana Maria"
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- Achieving efficient viability of akkermansia muciniphila during aerobic storage and gastrointestinal passage through calcium-alginate encapsulationPublication . Machado, Daniela; Fonseca, Mariana; Vedor, Rita; Barbosa, Joana Cristina; Gomes, Ana Maria
- Advances in extraction methods to recover added-value compounds from seaweeds: sustainability and functionalityPublication . Matos, Gabriela S.; Pereira, Sara G.; Genisheva, Zlatina A.; Gomes, Ana Maria; Teixeira, José A.; Rocha, Cristina M. R.Seaweeds are a renewable natural source of valuable macro and micronutrients that have attracted the attention of the scientists in the last years. Their medicinal properties were already recognized in the ancient traditional Chinese medicine, but only recently there has been a considerable increase in the study of these organisms in attempts to demonstrate their health benefits. The extraction process and conditions to be used for the obtention of value-added compounds from seaweeds depends mainly on the desired final product. Thermochemical conversion of seaweeds, using high temperatures and solvents (including water), to obtain high-value products with more potential applications continues to be an industrial practice, frequently with adverse impact on the environment and products’ functionality. However more recently, alternative methods and approaches have been suggested, searching not only to improve the process performance, but also to be less harmful for the environment. A biorefinery approach display a valuable idea of solving economic and environmental drawbacks, enabling less residues production close to the much recommended zero waste system. The aim of this work is to report about the new developed methods of seaweeds extractions and the potential application of the components extracted.
- Advancing circular nutrition: the development of a freeze-dried snack based on broccoli stalk powderPublication . Soares, Inês; Machado, Daniela; Vedor, Rita; Sousa, Sérgio; Orvalho, Telma; Dias, Sara; Alves, Marco; Gomes, Ana MariaAim: 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.
- Aggregation properties of probiotic strains under aerobic and anaerobic conditionsPublication . Machado, Daniela; Andrade, José Carlos; Barbosa, Joana Cristina; Costa, Francisca; Fonseca, Mariana; Almeida, Diana; Freitas, Ana Cristina; Gomes, Ana Maria
- Aggregation properties of probiotic strains under aerobic and anaerobic conditionsPublication . Machado, Daniela; Andrade, José Carlos; Barbosa, Joana Cristina; Costa, Francisca; Fonseca, Mariana; Almeida, Diana; Freitas, Ana Cristina; Gomes, Ana Maria
- Akkermansia muciniphila antimicrobial susceptibility profilePublication . Barbosa, Joana Cristina; Machado, Daniela; Almeida, Diana; Andrade, José Carlos; Freitas, Ana Cristina; Gomes, Ana Maria
- Akkermansia muciniphila encapsulated in calcium-alginate hydrogelated matrix: viability and stability over aerobic storage and simulated gastrointestinal conditionsPublication . Machado, Daniela; Fonseca, Mariana; Vedor, Rita; Sousa, Sérgio; Barbosa, Joana Cristina; Gomes, Ana MariaAkkermansia 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.
- Akkermansia muciniphila robustness towards different temperatures, atmospheres and gastrointestinal conditionsPublication . Freitas, Ana Cristina; Machado, Daniela; Almeida, Diana; Seabra, Catarina; Andrade, José Carlos; Gomes, Ana Maria
- Akkermansia muciniphila robustness towards different temperatures, atmospheres and gastrointestinal conditionsPublication . Freitas, Ana Cristina; Machado, Daniela; Almeida, Diana; Seabra, Catarina; Andrade, José Carlos; Gomes, Ana Maria
- Analytical approaches for proteomics and lipidomics of arsenic in algaePublication . Freitas, Ana Cristina; Gomes, Ana MariaArsenic (As) is an element with a complex chemistry found in relatively high concentrations in the marine environment. A diverse group of As compounds or As species exist in the marine environment and these are of importance to human health given their potential cytotoxicity. It has been pointed out that marine algae are the origin of such As compounds, since they accumulate arsenate from seawater and metabolize it into several organoarsenic species of both lipophilic and hydrophilic nature. In this chapter, it is intended to discuss lipidomics approaches for identification of the > 70 existing lipophilic arsenic species (arsenolipids) in algae which include arsenic incorporated into phospholipids, hydrocarbons, long-chain alcohols, and polyunsaturated fatty acids. In turn, proteomic analysis will also be presented and discussed in its role, for example, to investigate whether cells show a specific response or survival strategy when under arsenic-induced stress. Research on proteome involvement in stress and tolerance to arsenic offers new tools to understand the associated physiological and biochemical mechanisms connected with different algae responses. Protein biomarkers are also of interest to enable indication of quantitative changes in some physiological parameters as the result of stress or toxicity.