Browsing by Author "Morais, Alcina M. M. B."
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- a* values to follow lycopene concentration during ripening and storage of tomato (cv. Caruso)Publication . Schauwers, Axelle; Rocha, Ada M. C. N.; Morais, Alcina M. M. B.The ripening of tomato fruit is a highly regulated process during which colour, flavour, aroma and texture change in a coordinated manner. This research work aims to correlate the colour changes measured objectively with the lycopene concentration in tomatoes during ripening at room temperature (21 and 26°C). These results were compared with colour and lycopene content of pink and light red tomatoes stored at 14°C, temperature used to prevent ripening and therefore extend the shelf life of the fruits. The duration of heat treatment at 100ºC was previously optimized in order to release the maximum lycopene from chromoplasts during extraction. An a* value of 20 for the peel corresponds to an increase of lycopene content of Caruso tomato from 9 to 43 mg/100 g TSS, at room temperature. The shelf life of pink and light red tomatoes can be extended to two weeks at 14ºC without loss of lycopene content, presenting the same content as green tomatoes ripened at room temperature for one week.
- Alginate: Pharmaceutical and Medical ApplicationsPublication . Batista, Patrícia; Morais, Alcina M. M. B.; Pintado, Maria Manuela; Morais, Rui M. S. C.Due to their outstanding properties in terms of mild gelation conditions and simple functionalization, biocompatibility, low toxicity, biodegradability, non-antigenicity and chelating ability, as well as relatively low cost, alginates have been widely used in a variety of biomedical applications including tissue engineering and drug delivery systems. Smart alginate hydrogels for on-demand drug release in response to environmental stimuli and 3D bioprinting will play an important role in the future. These and the introduction of appropriate cell interactive features will be crucial for many tissue engineering applications. The focus of the present chapter is to highlight the great potential of the alginates as biomaterial for biomedical applications and to discuss the role that alginate-based materials are likely to play in biomedical applications in the future.
- Antibacterial and antioxidant potential of aqueous extracts of bio-residues from agrocybe cylindracea and pleurotus ostreatus myceliumPublication . Sousa, Ana Sofia; Nunes, Catarina; Barros, Joana; Ferreira, Inês; Freitas, Ana C.; Morais, Alcina M. M. B.; Nunes, João; Pintado, ManuelaThe production of fresh mushrooms results in a large quantity of bio-residues, which may account for more than 20% of a crop volume and contributes to production costs and environmental impact, if not used. These products consist mainly of stalks, mushrooms of irregular dimensions and shape and basal material. Thus, the main objective of MicoBioExtract project is the valorisation of these bio-residues and the development of add-value by-products with bioactive compounds such as polysaccharides and phenolic compounds produced by mushrooms. In the present work, the aqueous extracts from Agrocybe cylindracea byproducts (ACB) and Pleurotus ostreatus mycelium (POM) were evaluated for potential antioxidant and antimicrobial activities. Water soluble substances were extracted from mushrooms according to two different methods. In method 1 it was performed a hot extraction (extract 1A; 90 °C; 1 h; 500 rpms). In method 2, the biomass was submitted to an extraction at room temperature (extract 2B) and the resulting residue was extracted with hot water (extract 2C; 90 °C; 1 h; 500 rpms). The aqueous extracts from POM were obtained only by method 1. Extracts were lyophilized and their bioactivity evaluated measuring the antioxidant (ABTS, DPPH and ORAC) and antimicrobial (determination of the minimum inhibitory concentration – MIC) activities. The mutagenicity was also tested (Ames assay with and without S9). Moreover, it was determined the total phenolics content of the extracts and α and β – glucans (Folin Ciocalteu and Beta-Glucan Assay methods, respectively). The results obtained from antioxidant methods showed that all extracts from both mushrooms are a potential source of natural antioxidant and phenolic compounds. According to ABTS, extract 2B from ACB showed the best value with 8.48±0.33 mg ascorbic acid equivalent (AAE)/g dry extract and 4.14±0.52 mg AAE/g dry extract for POM. Regarding the antimicrobial activity, MIC results showed that ACB and POM extracts inhibited the growth of Gram- (Salmonella enteritidis) and Gram+ (Bacillus cereus and Listeria monocytogenes). Concerning the mutagenicity, the results showed no toxic effect except for extract 1A from ACB. Regarding the β-glucan content, the extracts from ACB presented higher content of β-glucan than the C extracts from POM. Thus, aqueous extracts from mushroom bio-residues showed potential antioxidant and antimicrobial properties and to develop a circular bioeconomy approach.
- Application of nisin and chitosan as antimicrobial agents in traditional cured and smoked “Alheira”Publication . Fonseca, S. C.; Jácome, S.; Pinheiro, R.; Alves, M. R.; Noronha, L.; Silva, J.; Almeida, G.; Todorov, S. D.; Pintado, M. E.; Gomes, A; Morais, Alcina M. M. B.; Vaz-Velho, M.; Teixeira, Paula
- Bioactive compounds from marine microalgae — health applicationsPublication . Raposo, M. Filomena de J.; Morais, R. M. S. C.; Morais, Alcina M. M. B.
- Bioconservação de alimentos tradicionais por adição de bactérias ácido-lácticas e das suas bacteriocinasPublication . Jácome, S. L.; Todorov, S. D.; Fonseca, S. C.; Pinheiro, R.; Guerreiro, J. S.; Monteiro, V.; Fernandes, P.; Noronha, L.; Almeida, Gonçalo; Gomes, Ana M. P.; Pintado, M. E.; Silva, Cristina L. M.; Morais, Alcina M. M. B.; Silva, Joana; Teixeira, Paula; Vaz-Velho, Manuela
- Biodegradable films with polysaccharides, proteins, and bioactive compounds from lobosphaera sp.: antioxidant and antimicrobial activitiesPublication . Martins, Valter F. R.; Lopes, Ana I.; Machado, Manuela; Costa, Eduardo M.; Ribeiro, Tânia B.; Poças, Fátima; Pintado, Manuela; Morais, Rui M. S. C.; Morais, Alcina M. M. B.Microalgae are a sustainable source of bioactive compounds and nutrients that do not compete with crops for arable land. Lobosphaera sp. was used to produce biodegradable films. Bioactive compounds, polysaccharides, and proteins were extracted from this microalga. The total phenolic content (TPC) and antioxidant activity (ABTS, DPPH, and ORAC) of the bioactive-rich extract were determined, and its composition was analyzed for phenolics using LC-ESI-QqTOF-HRMS and for lipids using GC-FID. The cytotoxicity of this extract on Caco-2 cells was also assessed. Different types of films were produced based on alginate (2%) (film A) and alginate with polysaccharides-rich (PS-rich) extract (0.5%) (film B); PS-rich extract and bioactive-rich extract (0.25%) (film C); protein-rich (P-rich) extract (0.5%) (film D); and P-rich extract and bioactive-rich extract (film E). The antioxidant activity and physical parameters of the films, such as thickness, color, water vapor permeability, solubility, tensile strength (TS), and elongation at break (EAB), were determined. The TPC of the bioactive-rich extract was 1.07 ± 0.05 mg GAE/100 mg DW, and its antioxidant activity was 2.44 ± 0.27, 1.67 ± 0.15, and 11.90 ± 1.22 µmol TE/100 mg DW for ABTS, DPPH, and ORAC, respectively. The extract showed no cytotoxicity to gut cells at concentrations equal to or below 1.0 mg/mL. Film E obtained the best results for the antioxidant activity, 451.06 ± 14.68 and 212.81 ± 39.12 µM TE/mg film for ABTS and DPPH, respectively. In addition, the films enriched with the bioactive-rich extract (films C and E) presented antimicrobial activity against Listeria monocytogenes. These films controlled the mold and yeast growth in strawberries during a four-day storage at 25 °C. All films were completely soluble in water and hydroethanolic solutions but only partially solubilized in acetic acid (3%). TS and EAB were not significantly different among the films. It was possible to produce biodegradable films using microalga Lobosphaera sp. with good bioactivity and physical characteristics.
- Biostimulant effect of two fucus sp. algal residues on pea, rice, and tomato germination and growthPublication . Sperotto, Raul A.; Rosa-Martínez, Elena; Martins, Valter F. R.; Pintado, Manuela; Morais, Rui M. S. C.; Morais, Alcina M. M. B.; Vasconcelos, Marta W.Introduction: Seaweed-based bioproducts are increasingly recognized for their phytostimulatory properties, promoting plant growth and enhancing resistance to various stresses. Notably, Fucus vesiculosus, a brown seaweed, has shown promise as a biostimulant1. Exopolysaccharides (EPSs) constitute different classes of organic macromolecules that can have multiple applications. This study investigates the bioestimulant effects of Fucus sp. on the germination and early growth of pea, rice, and tomato, utilizing two algal extracts—one with EPS and another without EPS. The goal was to assess the impact of the algal residues on seed germination and initial plant development and provide insights into their potential as sustainable biostimulants. Conclusions: The three crops responded differently to applying algae extracts in the substrate as a biostimulant. The most promising results were obtained for rice and tomato since they showed a biostimulating effect on crop growth in the early stages of development, which was demonstrated mainly in the significant increase in plant dry biomass. Ultimately, the algae residue without EPS (BS-EPS at both concentrations) gave better results than the algae residue with EPS, as it significantly promoted the development of rice and tomato seedlings.
- Can anti-listerial L AB strains, used as starter cultures, affect the sensory properties of a sausage-like smoked product?Publication . Jácome, Samuel L.; Fonseca, Susana; Pinheiro, Rita; Alvesa, Manuel Rui; Todorovb, Svetoslav; Noronha, Lúcia; Silva, Joana; Morais, Alcina M. M. B.; Teixeira, Paula; Vaz-Velho, Manuela
- Characterization on extraction conditions for 'starking" apple polyphenolox1dase (ppo)Publication . Rocha, A. M. C. N; Cano, M. P.; Galeazzi, A. M.; Morais, Alcina M. M. B.