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1.
Colloids Surf B Biointerfaces ; 170: 538-543, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29975901

RESUMO

Iron deficiency is the most common nutritional deficit worldwide. The goal of this work was to obtain iron-pectin beads by ionic gelation and evaluate their physiological behavior to support their potential application in the food industry. The beads were firstly analyzed by scanning electronic microscopy, and then physical-chemically characterized by performing swelling, thermogravimetric, porosimetry, Mössbauer spectroscopy and X-ray fluorescence analyses, as well as by determining the particle size. Then, physiological assays were carried out by exposing the beads to simulated gastric and intestinal environments, and determining the iron absorption and transepithelial transport into Caco-2/TC7 cells. Iron-pectin beads were spherical (diameter 1-2 mm), with high density (1.29 g/mL) and porosity (93.28%) at low pressure, indicating their high permeability even when exposed to low pressure. Swelling in simulated intestinal medium (pH 8) was higher than in simulated gastric medium. The source of iron [FeSO4 (control) or iron-pectin beads] did not have any significant effect on the mineral absorption. Regarding transport, the iron added to the apical pole of Caco-2/TC7 monolayers was recovered in the basal compartment, and this was proportional with the exposure time. After 4 h of incubation, the transport of iron arising from the beads was significantly higher than that of the iron from the control (FeSO4). For this reason, iron-pectin beads appear as an interesting system to overcome the low efficiency of iron transport, being a potential strategy to enrich food products with iron, without altering the sensory properties.


Assuntos
Sistemas de Liberação de Medicamentos , Intestinos/citologia , Ferro/administração & dosagem , Ferro/metabolismo , Pectinas/química , Células CACO-2 , Humanos , Ferro/química , Tamanho da Partícula , Propriedades de Superfície
2.
Appl Radiat Isot ; 57(4): 497-500, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12361328

RESUMO

The occurrence of subfossil material in bottom sediments of Couve Island, Ubatuba region, São Paulo State, is confirmed. The analyzed material consists of a bivalve shell that was dated by the electron spin resonance technique. By the additive irradiation method an archaeological absorbed dose of (25 +/- 5) Gy was obtained and calibration with other dating works in the same area allows the inference of an age of (25 +/- 5) x 10(2) years. The importance of this finding and its paleoecological implications could contribute to elucidating the nature of short-term environmental changes in the Brazilian coastline during the Holocene, as well as becoming an important tool to the understanding of the distribution and biological aspects of the bivalve fauna.


Assuntos
Fósseis , Moluscos , Animais , Brasil , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Raios gama , Sedimentos Geológicos , Paleontologia , Fatores de Tempo
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