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Browsing by Author "Almeida, I. M. C."

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  • Isoflavones in food supplements: chemical profile, label accordance and permeability study in Caco-2 cells
    Publication . Almeida, I. M. C.; Rodrigues, F.; Sarmento, B.; Alves, R. C.; Oliveira, M. B. P. P.
    Consumers nowadays are playing an active role in their health-care. A special case is the increasing number of women, who are reluctant to use exogenous hormone therapy for the treatment of menopausal symptoms and are looking for complementary therapies. However, food supplements are not clearly regulated in Europe. The EFSA has only recently begun to address the issues of botanical safety and purity regulation, leading to a variability of content, standardization, dosage, and purity of available products. In this study, isoflavones (puerarin, daidzin, genistin, daidzein, glycitein, genistein, formononetin, prunetin, and biochanin A) from food supplements (n = 15) for menopausal symptoms relief are evaluated and compared with the labelled information. Only four supplements complied with the recommendations made by the EC on the tolerable thresholds. The intestinal bioavailability of these compounds was investigated using Caco-2 cells. The apparent permeability coefficients of the selected isoflavonoids across the Caco-2 cells were affected by the isoflavone concentration and product matrix.
    2015-01Journal article Restricted access Show more
  • Teas, dietary supplements and fruit juices: a comparative study regarding antioxidant activity and bioactive compounds
    Publication . Costa, A. S. G.; Nunes, M. A.; Almeida, I. M. C.; Carvalho, M. R.; Barroso, M. Fátima; Alves, Rita C.; Oliveira, M. Beatriz P. P.
    Nowadays, new emerging products claiming antioxidant properties are becoming more frequent. However, information about this topic in their labels is usually scarce. In this paper, we analyzed total phenolics, total flavonoids and ascorbic acid contents, as well as DPPH scavenging activity of several commercial samples, namely green tea and other herbal infusions, dietary supplements, and fruit juices, available in the Portuguese market. In general, beverages containing green tea and hibiscus showed higher phenolics contents (including flavonoids) and antioxidant activity than those without these ingredients. A borututu infusion presented the lowest concentrations of bioactive compounds and scavenging activity, due to the low recommended amount of plant to prepare the beverage. Some juices without antioxidant claims in the label presented similar values to those with it.
    2012Journal article Open access Show more