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- Brazilian fruit pulps as functional foods and additives: evaluation of bioactive compoundsPublication . Paz, Mário; Gúllon, Patricia; Barroso, M. Fátima; Carvalho, Ana P.; Domingues, Valentina F.; Gomes, Ana M.; Becker, Helena; Longhinotti, Elisane; Delerue-Matos, CristinaEight tropical fruit pulps from Brazil were simultaneously characterised in terms of their antioxidant and antimicrobial properties. Antioxidant activity was screened by DPPH radical scavenging activity (126-3987 mg TE/100 g DW) and ferric reduction activity power (368-20819 mg AAE/100 g DW), and complemented with total phenolic content (329-12466 mg GAE/100 g DW) and total flavonoid content measurements (46-672 mg EE/100 g DW), whereas antimicrobial activity was tested against the most frequently found food pathogens. Acerola and acai presented the highest values for the antioxidant-related measurements. Direct correlations between these measurements could be observed for some of the fruits. Tamarind exhibited the broadest antimicrobial potential, having revealed growth inhibition of Pseudomonas aeruginosa. Escherichia coli, Listeria monocytogenes, Salmonella sp. and Staphylococcus aureus. Acai and tamarind extracts presented an inverse relationship between antibacterial and antioxidant activities, and therefore, the antibacterial activity cannot be attributed (only) to phenolic compounds.
- Microwave-assisted extraction in goji berries: effect on composition and bioactivity, evaluated through conventional and nonconventional methodologiesPublication . Carvalho, Ana P.; Mendes, Marta; Moreira, Manuela M.; Cruz, Diana; Magalhães, Júlia M. C. S.; Barroso, M. Fátima; Ramalhosa, M. J.; Duarte, Abel; Guido, Luís; Gomes, Ana M. P.; Matos, Cristina DelerueThis study aimed to evaluate the effect of microwave-assisted extraction (MAE) parameters on the composition and bioactivity of goji (Lycium barbarum) extracts. Extracts were obtained under a central composite design combination of experimental conditions, and characterised through HPLC-DAD; their bioactive capacity was ascertained for antimicrobial and antioxidant capacity, the later by spectrophotometric [2,2-azinobis (3- ethylbenzothiazoline-6-sulfonic acid) diammonium salt-radical scavenging activity assay – 413–748 mg ascorbic acid equivalents/100 g DW and oxygen radical absorbance capacity – 1901–2292 mg trolox equivalents/ 100 g DW] and electrochemical (DNA-based sensor – 3571–6602 mg ascorbic acid/100 g DW) methods. The quantitative profile of phenolic compounds was strongly dependent on MAE conditions. Significant correlations were found between the presence of several flavonoids and solvent composition, as well as between phenolic acids with methoxy group and the response to DNA-based sensor. Results may improve targeted extractions for specific compounds, leading to the achievement of extracts richer in antioxidant capacity, as well as in the tailoring of the biosensor response sensitivity to the composition of the extracts under analysis.
- Screening of bioactive properties in brown algae from the Northwest Iberian PeninsulaPublication . Silva, Aurora; Rodrigues, Carla; Garcia-Oliveira, Paula; Lourenco-Lopes, Catarina; Silva, Sofia A.; Garcia-Perez, Pascual; Carvalho, Ana P.; Domingues, Valentina F.; Barroso, M. Fátima; Delerue-Matos, Cristina; Simal-Gandara, Jesus; Prieto, Miguel A.Algae are an underexploited source of natural bioactive compounds in Western countries, so an increasing interest in the valorization of these marine organisms has emerged in recent years. In this work, the effect of extracting solvent on the extraction yield, phenolic content, antioxidant capacity, and antimicrobial activity of nine brown macroalgae species (Ascophyllum nodosum, Himanthalia elongata, Undaria pinnatifida, Pelvetia canaliculata, Saccharina latissima, Bifurcaria bifurcata, Laminaria ochroleuca, Sargassum muticum, and Fucus spiralis) was assessed. Total phenolic content (TPC) and the antioxidant properties of extracts by different assays: radical scavenging activity (DPPH-RSA) and ferric reducing antioxidant power (FRAP) were performed. The antimicrobial activity of extracts was studied against six different foodborne microorganisms: Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Escherichia coli, Salmonella enteritidis, and Pseudomonas aeruginosa. The highest extraction yield was achieved in ethanolic extracts. However, the highest TPC and FRAP values were obtained on the ethyl acetate extracts, especially from A. nodosum. Concerning algal species, the highest TPC and FRAP values were found in A. nodosum, while the highest DPPH-RSA values were achieved in the hexane extracts of B. bifurcata. The antimicrobial activity of algal extracts varied according to the solvent and alga selected, suggesting the species- and solvent-dependent behavior of this property, with B. bifurcata extracts showing the highest results for a wide range of bacteria. Our results provide insight on the characterization of widespread brown algae in the coasts of the North-Western region of the Iberian Peninsula, reflecting multiple health-enhancing properties which may lead to their exploitation in food, pharmacological, and cosmetic industries.
- Use of coffee by-products for the cultivation of Pleurotus citrinopileatus and Pleurotus salmoneo-stramineus and its impact on biological properties of extracts thereofPublication . Freitas, Ana C.; Antunes, Mariana B.; Rodrigues, Dina; Sousa, Sérgio; Amorim, Manuela; Barroso, Maria F.; Carvalho, Ana; Ferrador, Sandra M.; Gomes, Ana M.Incorporating spent coffee grounds (SCGs), a by-product from coffee brewing, in growth substrate of beneficial edible mushrooms is an approach that has to be further studied due to its potential positive outcomes: environmental impact mitigation, production costs reduction and beneficial impact on consumer health. Hence, cultivation of Pleurotus citrinopileatus and Pleurotus salmoneo-stramineus was tested using SCG which enabled maximum production yield of P. citrinopileatus which was of 25.1% (w/w). Variable antidiabetic potential was observed between aqueous and enzymatic extracts (3.8%–29% inhibition) regardless species and substrates, whereas aqueous extract of P. citrinopileatus grown in substrate without SCG stood out presenting the highest antioxidant activity and inhibition activity of angiotensin I-converting enzyme (IC50 = 123 lg mL 1). Ethanolic and aqueous extracts of both Pleurotus species grown in the presence or absence of SGC proved to be an interesting prebiotic source for growth of Bifidobacterium animalis Bo in comparison with fructooligosaccharides (FOS).