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- Total antioxidant activity and trace elements in human milk: the first 4 months of breast-feedingPublication . Matos, Carla; Moutinho, Carla; Balcão, Victor; Almeida, Cristina; Ribeiro, Marta; Marques, Agostinho Franklim; Guerra, AntónioThe content of many nutrients in breast milk are dependent on the nutritional status of the lactating woman. This is particularly true for fat and water-soluble vitamins, some of which have antioxidant properties. The aim of the study entertained herein was to evaluate the changes in total antioxidant status of human milk during the first 4 months of lactation, and to correlate such changes with the contents in specific antioxidant oligoelements (Cu, Zn, Mn and Se). Milk samples were collected from (31) lactating women recruited at the Service of Obstetrics of the Hospital de São João in Porto, after 1, 4, 8, 12 and 16 weeks after birth. The total antioxidant status (TAS) of human milk was measured by the Randox® commercial kit and trace metals by ICP-MS (inductively coupled plasma-mass spectrometry). The results found for TAS and oligoelements under study show a decrease in the concentration of these parameters from 7 days to 4 months of breast-feeding and significant correlations (p < 0.05) were found between TAS and Cu, Zn and Se (not Mn). The decreases of Cu, Zn and Se were also correlated, but not proportional between them, suggesting diverse excretion mechanisms for all. Between primipara and multipara women, a significant difference was found only for Cu and Zn concentrations at 7 days of lactation, but not for the other metals or TAS. With respect to the mother’s age, no correlation was found, either for trace metal concentrations or TAS.
- Fatty Acid Profile of Human Milk of Portuguese Lactating Women: Prospective Study from the 1st to the 16th Week of LactationPublication . Ribeiro, M.; Balcão, Victor; Guimaraes, H.; Rocha, G.; Moutinho, Carla; Matos, Carla; Almeida, Cristina; Casal, S.; Guerra, A.Background/Aims: Fatty acid (FA) composition varies over the course of the day and during lactation. The aim of this study was to evaluate FA composition and its compositional stability in human milk, from day 7 to week 16 of lactation. Methods: Human milk was collected from all feedings over 24 h at day 7 and weeks 4, 8, 12 and 16 of lactation in 31 lactating women. FAs were analyzed through gas chromatography. Comparisons were made with analysis of variance. Results: Total monounsaturated FAs decreased from 33.04 ± 2.58% wt/wt at day 7 to 31.48 ± 3.32% wt/wt at week 16 of lactation, much at the expenses of the decrease in the major monounsaturated FA found in human milk, oleic acid. Main polyunsaturated FAs n-6 and n-3 showed fluctuations from day 7 up to week 16 of lactation, but with no statistical significance. Arachidonic acid significantly decreased from transitional to mature milk. Conclusions: The FA profile obtained throughout the study time points presented very low levels of oleic acid and very high linoleic acid/α-linoleic acid ratios which reflect recent changes in Portuguese women’s food patterns. Despite this, the ascorbate/dehydroascorbate ratio remained constant during the study, suggesting a protective metabolic mechanism.
- Proteins and peptides: non-invasive deliveryPublication . Balcão, Victor; Moutinho, Carla
- Nanoencapsulation of bovine lactoferrin for food and biopharmaceutical applicationsPublication . Balcão, Victor; Costa, Carla I.; Matos, Carla; Moutinho, Carla; Amorim, Manuela; Pintado, Manuela E.; Gomes, Ana P.; Vila, Marta M.; Teixeira, José A.Lactoferrin has for long captured the interest of many researchers as a natural compound with a wide variety of uses. Lactoferrin is a monomeric, iron-binding 80 kDa glycoprotein, and appears to be the subfraction of whey with the best documented antiviral, antimicrobial, anticancer and immune modulating/enhancing effects. It belongs to the family of transferrin proteins, and serves to control iron levels in body fluids by sequestering and solubilizing ferric iron. In the present research effort, production of lactoferrin derivatives (starting from a purified commercial extract), encompassing full stabilization of its three-dimensional structure, has been attempted via nanoencapsulation within lipid nanovesicles, integrating a multiple water-in-oil-in-water emulsion. Long-term storage of the multiple nanoemulsions produced did not lead to leaching of protein, thus proving the effectiveness of the encapsulation procedure. Furthermore, lactoferrin nanovesicle derivatives prepared under optimal conditions were successfully employed at lab-scale antimicrobial trials.
- 160 Fatty Acid Composition of Human Milk in a Portuguese Urban Population:Prospective Study from 7 Days to 16 Weeks of LactationPublication . Ribeiro, M; Balcão, Victor; Guimaraes, H; Rocha, G; Moutinho, Carla; Casal, S; Oliveira, B; Guerra, A
- Design of a lipid nanovesicle system encapsulating bacteriophages integrated in a multiple emulsion formulation: A proof-of-conceptPublication . Balcão, V. M.; Azevedo, A.F.; Castro, L.M.; Costa, Carla Isabel; Santos, S. R. B.; Matos, C. M.; Moutinho, C. G.; Teixeira, J. A.Development of a biotechnological process for the inhalational administration of a bacteriophage was pursued, using strategies of nanoencapsulation within lipid nanovesicles. As a proof-of-concept for the nanoencapsulation strategy, a bacteriophage with broad lytic spectrum was entrapped within W/O/W multiple nanoemulsions. Physicochemical characterization of the optimized bacteriophage-encasing nanovesicles encompassed determination of particle hydrodynamic size, size distribution and particle charge via DLS, surface morphology via CRYO-SEM, and thermal analysis via DSC, whereas antimicrobial activity of the nanoemulsions produced was assessed in vitro using several bacterial strains. The optimized nanosystems showed no phase separation and encompassed nanovesicles with an average size of ca. 114 nm and an average Zeta Potential of ca. -13 mV, which were maintained stable over a storage timeframe of ca. 3 months.
- Alimentos potenciadores de saúde: produtos lácteos probióticosPublication . Balcão, Victor; Moutinho, Carla; Matos, Carla; Almeida, CristinaOs alimentos probióticos em geral têm sido definidos como sendo “suplementos alimentares incorporando microorganismos vivos (bactérias probióticas) que afectam beneficamente o hospedeiro, melhorando o equilíbrio da sua microflora a nível intestinal”. O leite e os produtos lácteos em geral contêm vários biocomponentes que fornecem elementos nutritivos críticos e protecção imunológica, bem como substâncias biologicamente activas tanto a recém-nascidos como a adultos, pelo que estes alimentos pertencem ao grupo dos chamados alimentos funcionais. Produtos alimentares à base de leite inteiro ou lácteos fortificados ou enriquecidos podem, de facto, produzir efeitos potencialmente benéficos na melhoria da saúde humana e na prevenção de doenças, quando consumidos como parte de uma dieta variada e de forma regular.
- Caracterização e valorização do lagostim Procambarus clarkiiPublication . Martins, Pedro Maurício; Balcão, Victor; Nunes, BrunoCom este trabalho pretendeu-se caracterizar e valorizar o lagostim vermelho da louisiana, espécie invasiva e que actualmente representa uma praga ambiental no território nacional. Desenvolveu-se uma dieta específica para o aumento da massa corporal da espécie em cativeiro e, posteriormente, procedeu-se à extracção de biocompostos com potenciais aplicações farmacêuticas, dermocosméticas e alimentares, nomeadamente o biopolímero quitina (rendimento de 22.06% ± 5.79 (m/m)) e o pigmento antioxidante astaxantina (rendimento de 4.40% ± 2.24 % (m/m)). The main goal of this work was to characterize and add value to louisiana’s red crawfish, an invasive crustacean species that currently represents an environmental plague within the portuguese territory. A specific diet was developed for the crustaceans in captivity, to allow an effective increase of their body mass and weight and, subsequently, biocompounds with potential importance in pharmaceutical, dermocosmetic and food applications were extracted,namely the biopolymer chitin (yield of 22.06% ± 5.79 (w/w)) and the antioxidant pigment astaxanthin (yield of 4.40% ± 2.24 % (w/w)).
- Changes in the pool of free fatty acids in ovine, bovine and caprine milk fats, effected by viable cells and cell-free extracts of Lactococcus lactis and Debaryomyces vanrijiaePublication . Regado, Mafalda A.; Cristóvão, Betina M.; Tavaria, Freni K.; Ferreira, João Paulo; Moutinho, Carla Guimarães; Balcão, Victor; Xavier Malcata, F.Lipolysis catalysed by lipases, native or released by natural microflora in milk, plays a key role in development of aroma and flavour throughout cheese ripening. This research effort was aimed at a deeper understanding of the action of two wild strains used in traditional ewe’s milk cheesemaking in Portugal, viz. Lactococcus lactis and Debaryomyces vanrijiae. They were both tested as viable cells and cell-free extracts – using bovine, ovine and caprine milk fat emulsions as model substrates. Hydrolysis reactions were carried out at 30 and 37 °C, in the case of L. lactis and D. vanrijiae, respectively; the contents of short- and medium-chain fatty acids were determined by high pressure liquid chromatography. Our experimental results showed general trends, viz. preferential depletion of medium chain fatty acids throughout the whole reaction time. However, distinct patterns were observed towards different substrates, depending on the source and form of the biocatalyst at stake.
- Natural oxidants and ageing: myth or paradox?Publication . Nunes, Bruno; Balcão, VictorOs danos oxidativos podem ser prevenidos in vivo através da actividade protectora de antioxidantes biológicos (enzimáticos e não-enzimáticos). A importância dos antioxidantes biológicos é tal que, na sua ausência a vida estaria continuamente sob a ameaça da oxidação. Este fenómeno interfere com a estrutura, enovelamento e função das proteínas, com a integridade dos lípidos membranares e com a estrutura do DNA; a oxidação resulta também no processo de envelhecimento, através da acumulação de danos nas estruturas subcelulares.
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