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- 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.
- Sardine canning byproducts as sources of functional ingredientsPublication . Carvalho, Ana P.; Amorim, Maria Manuela; Rodríguez-Alcalá, Luís; Fontecha, Javier; Castro, Paula M. L.; Pintado, Manuela E.Sardine byproducts generated during the canning process entail a potential opportunity to drive them into a chain of high-added-value compounds while simultaneously decreasing the environmental impact of their discharge. This paper describes and discusses the biochemical variation of solid and liquid byproducts generated during the sardine canning process during one complete year. Additionally, byproducts were also evaluated in terms of their degradation over time as monitored through microbiological and chemical analysis. Finally, their valorization was ascertained through the recovery of lipid fractions rich in ω3 polyunsaturated fatty acids (PUFAs) as well as protein fractions with antihypertensive activity (ACE). The variability of the biochemical composition of byproducts during the year was significant, especially in terms of lipid content, and their degradation was strongly dependent on the conditions under which they were collected and stored. Both liquid and solid byproducts present ω6/ω3 ratios between 0.05 and 0.18 and thrombogenic indexes between 0.27 and 0.57, whereas low-molecular-weight fractions of protein extracts (<3 kDa) exhibited the strongest ACE activity (IC50 = 51 μg/mL). The potential viability of using liquid byproducts as sources of functional ingredients is an interesting alternative to the management of these effluents in the fish canning industry.
- 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.