Browsing by Author "Pintado, M. Manuela"
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- Antimicrobial activity of organic acids against some common food spoilage and pathogenic microorganismsPublication . Sorathiya, Kavita; Melo, Adma; Rodrigues, Cristina; Paulico, Luís; Barracosa, Rita; Correia, Daniela; Hogg, Maria Conceição; Pintado, M. ManuelaIntroduction: In recent years, the food industry is challenge of producing high-quality products using natural preservatives instead of synthetic ones, driven by increasing consumer demand for clean-label food products. Organic acids, which are prevalent in fruits and medicinal plants, possess well-documented antioxidant, antibacterial, and anti-inflammatory properties that are beneficial to human health (1). These acids have potential as alternative preservatives due to their antimicrobial activity and GRAS (Generally Recognized as Safe) status. They are utilized as antimicrobial agents, antioxidants, acidulants, flavor enhancers, and pH adjusters in various food products (2). Additionally, organic acids help enhance nutritional and physicochemical properties. As a natural approach to inhibiting food contaminants and pathogens, their antimicrobial properties contribute to improved food safety and extended shelf life (3). The objective of this study was to investigate the antimicrobial activity of organic acids against common food spoilage and pathogenic microorganisms for potential application in food formulation. Objective: The objective of this study was to investigate the antimicrobial activity of organic acids against food spoilage microorganisms. Conclusion: The organic acids tested showed significant antimicrobial potential at low concentrations, particularly lactic and propionic acids. Future studies will incorporate the most promising acids as substitutes for synthetic preservatives to verify their ability to maintain antimicrobial effectiveness over time when incorporated into foods.
- Biocompatibility of salix viminalis, salix atrocinerea and salix fragilisPublication . Silva, Sara; Veiga, Mariana; Costa, Eduardo; Costa, Célia; Faustino, Margarida; Ramos, Patricia A. B.; Santos, Sónia A. O.; Freire, Carmen S. R.; Silva, Artur M. S.; Silvestre, Armando J. D.; Pintado, M. Manuela
- Criação de valor com os resíduos e subprodutos alimentaresPublication . Pintado, M. Manuela
- Edible packaging: a vehicle for functional compoundsPublication . Pereira, Joana O.; Pintado, M. ManuelaNowadays, innovations constantly appear in food packaging, which lead to a demand for new foods, always aiming at creating a more efficient quality preservation system. Edible coatings and films are a good attempt to increase the storability of foods, controlling gas exchange, moisture, solutes migration, and oxidative reaction rates. In addition to these gains, edible coating/films can be used as carriers of bioactive compounds to improve the quality and enhance the nutritional value of food products, such as antimicrobials, antioxidants, flavors, probiotics, and other components, such as nutraceuticals or basic nutrients. Therefore, these approaches, in addition to being used to prolong shelf life, also provide functionality to food products. When the functional compounds are incorporated into the edible coating/film to perform their functions, they became a benefit for food as well as for consumers. Furthermore, the functional compounds are protected from the external factors and controlled release is allowed. In this sense, the aim of this chapter is to analyze the potential use of edible coatings and films incorporated with functional compounds, solve the disadvantages of direct application, and find the correct combination between the food product and the edible coating/film, which will ensure the success of the technology.
- Nutritional characterization of acorn flour (a traditional component of the Mediterranean gastronomical folklore)Publication . Silva, Sara; Costa, Eduardo M.; Borges, André B.; Carvalho, Ana P.; Monteiro, Maria João; Pintado, M. Manuela
- P82 Peptide fraction identification by SE-HPLC and LC-MS/MS analysis of the body mucus from Portugal coastal fish Halobatrachus didactylusPublication . Cunha, M.; Coscueta, E. R.; Brassesco, M. E.; Almada, F.; Gonçalves, D.; Pintado, M. ManuelaThe mucus covers the fish's body, working as a protective barrier. Besides physical protection, mucus provides molecules that protect the fish from pathogens damaging 1,2. These include antimicrobial peptides secreted in the mucus, which play an essential role in defense against microbial pathogens since these belong to the innate immune system2,3. In this study, two adult Halobatrachus didactylus individuals were captured from the wild in Sesimbra. Then, mucus collection was performed by scraping the dorsal-lateral body of the fish with a sponge. Our objective was the identification of new peptides with bioactive potential in mucus samples by chromatography analysis. Size exclusion highperformance liquid chromatography (SE-HPLC) analysis performed on mucus samples from the two individuals revealed a similar profile with an intense highlight peak which resulted in a distribution of about 775 Dalton. With interest in that peak, the two mucus samples were pooled for fractionation by SEC. The resulting fraction was analyzed by liquid chromatography-tandem mass spectrometry (LCMS/MS) to identify the most probable peptide sequences. Identification from databases did not provide reliable results, indicating a lack of information on the matrix analyzed. We resorted to de novo sequencing with good results using PEAKS Studio software. Five identified peptides were selected according to their bioactivities predicted in silico. Furthermore, the five identified peptides were synthesized, and the molecular size was validated by SE-HPLC analysis. Overall, this chromatographic approach enabled the identification of promising peptides, which bioactivities will be evaluated in vitro in future work.
- Study of antimicrobial activity and atomic force microscopy imaging of the action mechanism of cashew tree gumPublication . Campos, Débora A.; Ribeiro, Alexandra C.; Costa, Eduardo M.; Fernandes, João C.; Tavaria, Freni K.; Araruna, Felipe Bastos; Eiras, Carla; Eaton, Peter; Leite, José Roberto S. A.; Pintado, M. ManuelaThe aim of this work was to evaluate the antimicrobial potential of two grades of cashew tree gum (crude and purified) against eight microorganisms and to analyze the mechanism of cashew tree gum antimicrobial action via atomic force microscopy (AFM) imaging. The results indicated strong antimicrobial properties of pure cashew tree gum against all tested microorganisms, except for Candida albicans and Lactobacillus acidophilus. On the other hand crude cashew gum showed antimicrobial activity only against Gram-positive bacteria (MRSA, MSSA, Listeria innocua and Enterococcus faecium). Atomic force microscopy imaging showed that pure cashew tree gum lead to bacterial cell collapse. In conclusion cashew tree gum presented relevant antimicrobial activity against most of the studied bacteria, and the purification of the cashew gum affected its antimicrobial spectrum.
- The antimicrobial action of chitosan against the wine spoilage yeasts Brettanomyces/DekkeraPublication . Ferreira, Delfim; Moreira, Diana; Costa, Eduardo M.; Silva, Sara; Pintado, M. Manuela; Couto, José AntónioYeasts of the genera Dekkera and Brettanomyces are well known to be involved in the production of volatile phenols in wines imparting aroma defects that may affect wine quality. The monitoring and control of these organisms is of major importance for wine producers. This study aimed to evaluate the effect of chitosan, a natural polysaccharide, on the survival of Brettanomyces/Dekkera and on some physicochemical aspects of wine (pH value, colour intensity and hue, anthocyanin content and antioxidant capacity). Minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) values were determined for 8 strains of Brettanomyces/Dekkera by the broth microdilution technique. The results show that chitosan inhibits the growth of Brettanomyces/Dekkera at concentrations ranging from 0.20 to 0.50 mg/ml, depending on the molecular weight of the chitosan molecules and on the assayed strain. The low molecular weight (LMW) chitosan presented the smaller MIC values. Time-kill assays performed in wine added of LMW chitosan revealed reduction of yeast cell viability over time. Furthermore, chitosan affected some physicochemical characteristics of wine, particularly the hue and colour intensity. Relevant data, potentially useful for the establishment of regimes comprising the use of chitosan for the control of Dekkera/Brettanomyces yeasts in wine, is presented.
- The Health-Promoting Potential of Salix spp. Bark Polar Extracts: Key Insights on Phenolic Composition and In Vitro Bioactivity and BiocompatibilityPublication . Ramos, Patrícia A. B.; Moreirinha, Catarina; Silva, Sara; Costa, Eduardo M.; Veiga, Mariana; Coscueta, Ezequiel R.; Santos, Sónia A. O.; Almeida, Adelaide; Pintado, M. Manuela; Freire, Carmen S. R.; Silva, Artur M. S.; Silvestre, Armano J. D.Salix spp. have been exploited for energy generation, along with folk medicine use of bark extracts for antipyretic and analgesic benefits. Bark phenolic components, rather than salicin, have demonstrated interesting bioactivities, which may ensure the sustainable bioprospection of Salix bark. Therefore, this study highlights the detailed phenolic characterization, as well as the in vitro antioxidant, anti-hypertensive, Staphylococcus aureus growth inhibitory effects, and biocompatibility of Salix atrocinerea Brot., Salix fragilis L., and Salix viminalis L. bark polar extracts. Fifteen phenolic compounds were characterized by ultra-high-performance liquid chromatography-ultraviolet detection-mass spectrometry analysis, from which two flavan-3-ols, an acetophenone, five flavanones, and a flavonol were detected, for the first time, as their bark components. Salix bark extracts demonstrated strong free radical scavenging activity (5.58–23.62 µg mL−1 IC50 range), effective inhibition on angiotensin-I converting enzyme (58–84%), and S. aureus bactericidal action at 1250–2500 µg mL−1 (6–8 log CFU mL−1 reduction range). All tested Salix bark extracts did not show cytotoxic potential against Caco-2 cells, as well as S. atrocinerea Brot. and S. fragilis L. extracts at 625 and 1250 µg mL−1 against HaCaT and L929 cells. These valuable findings can pave innovative and safer food, nutraceutical, and/or cosmetic applications of Salix bark phenolic-containing fractions.