Browsing by Author "Silvestre, Armando J.D."
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- Phenolic compounds as modulators of gut microbiota composition: an in vitro batch fecal fermentation approachPublication . Pais, Adriana C. S.; Ribeiro, Tânia B.; Coscueta, Ezequiel R.; Salsinha, Ana Sofia; Pintado, Maria Manuela; Silvestre, Armando J.D.; Santos, Sónia A. O.The human diet comprises a variety of bioactive compounds, such as phenolic compounds which are widely present in vegetables and fruits that confer numerous health benefits.1 However, the health benefits of these compounds appear to be directly influenced by a number of factors, including their bidirectional relationship with gut microbiota,1,2 as these compounds are metabolized by these microorganisms, and, simultaneously, modulate their composition.1,3 Nevertheless, knowledge about the impact of these dietary compounds have individually on human gut microbiota remains limited 3,4. Three phenolic compounds (ellagic acid, naringenin, and phloroglucinol) were subjected to an in vitro batch fermentation with a pool of fresh human fecal samples collected from healthy donors. Subsequently, the samples were further analyzed by 16S amplicon metagenomics sequencing and their short-chain fatty acids (SCFAs) profile was determined by gas chromatography with a flame ionization detector (GC-FID). Ellagic acid and phloroglucinol exhibited prebiotic properties, as evidenced by the production of specific SCFAs, including acetic, propanoic, and butyric acids. Furthermore, these compounds positively influenced the growth of beneficial genera of bacteria, such as Lactobacillus and Bifidobacterium. In contrast, naringenin exerted an influence on other genera with a pathogenic character, such as Escherichia and Salmonella. These findings contribute significantly to our understanding of how these phenolic compounds influence the gut microbiota composition. As a future perspective, this knowledge could be relevant to the development of new formulations in the nutraceutical or pharmaceutical areas. Furthermore, studying of phenolic compounds in combination may be a crucial step in future research to achieve a more diverse and well-balanced gut microbiota ecosystem.
- Strategies to preserve postharvest quality of horticultural crops and superficial scald control: from diphenylamine antioxidant usage to more recent approachesPublication . Dias, Cindy; Amaro, A. L.; Salvador, Ângelo C.; Silvestre, Armando J.D.; Rocha, Sílvia M.; Isidoro, Nélson; Pintado, ManuelaHorticultural crops are vulnerable to several disorders, which affect their physiological and organoleptic quality. For about forty years, the control of physiological disorders (such as superficial scald) in horticultural crops, particularly in fruit, was achieved through the application of the antioxidant diphenylamine (DPA), usually combined with controlled atmosphere (CA) conditions. However, identification of DPA residues and metabolites in treated fruits, associated with thei toxicity, banned the use of this antioxidant in Europe. This triggered the urgent need for novel and, ideally, natural and sustainable alternatives, combined with adequate storage conditions to protect cultivars from harmful agents. This review systematizes the state-of-the-art DPA application on several fresh cultivars, such as apples, pears, and vegetables (potatoes, spinach, etc.), as well as the possible mechanisms of the action and effects of DPA, emphasizing its antioxidant properties. Alternative methods to DPA are also discussed, as well as respective effects and limitations. Recent research on scald development molecular pathways are highlighted to open new non-chemical strategies opportunities. This appraisal shows that most of the current solutions have not lead to satisfactory commercial results; thus, further research aimed to understand the mechanisms underlying postharvest disorders and to design sustainable and safe solutions to improve horticultural products storage is needed.