RESUMO
In this work, new biotechnological procedures have been optimized on the basis of immobilization in alginate of bionts isolated from the lichen C. substellata. From these immobilizates, soluble and biologically active phenolics can be obtained. During bionts-immobilization, stictic, norstictic and usnic acids were secreted to the medium. The amount produced of each of them differed depending on the immobilization time, the precursor supplied and the type of biont used. Greater amounts of stictic acid were detected and maintained over time in all bioreactors. The opposite occurs in non-immobilized thallus. Virtually, all lichen phenols exhibit antioxidant activity to a greater or lesser degree, so that the antioxidant capacity of stictic acid (82.13% oxidation inhibition) was tested. The soluble extract of immobilized algae co-incubated in sodium acetate with fungal hyphae contained carbohydrates and exhibited a potent antioxidant capacity after 13â¯days of immobilization (94.87%). Therefore, attempts have been made to relate both parameters. On the other hand, the growth of Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae was inhibited by phenolic compounds produced by immobilizates, although the organic extract of the whole lichen showed the highest activity due to a possible synergy with other indeterminate compounds. Thus, C. substellata immobilized bionts are a potential source of different natural antioxidant and antimicrobial compounds.
Assuntos
Antioxidantes/isolamento & purificação , Clorófitas/química , Líquens/microbiologia , Fenóis/isolamento & purificação , Compostos Fitoquímicos/isolamento & purificação , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Antioxidantes/farmacologia , Carboidratos/isolamento & purificação , Células Imobilizadas , Fungos/química , Fenóis/farmacologia , Compostos Fitoquímicos/farmacologiaRESUMO
INTRODUCTION: Carotenoids are plant pigment with important biological activities in humans, such as provitamin-A among others. At present, there are no individual carotenoid intake data in the Dominican population, which is at risk of vitamin A deficiency and has an important percentage of overweight and obese individuals . OBJECTIVE: To assess the individual components of vitamin A intake (retinol, α-carotene, ß-carotene and ß-cryptoxanthin) and that of other relevant dietary carotenoids like lutein, zeaxanthin and lycopene of Dominican daily food intake. METHODS: Fifty overweigth and obese subjects (22-69 y). Individual carotenoid intake, from whole diet and from the ingestion of fruits and vegetables, was determined using three 24 h diet recalls and a specific carotenoid database. Retinol, macronutrient and energy intake were calculated using DIAL® software. RESULTS: The total carotenoid intake was 6363.2 µg/day, 56. 1% corresponding to provitamin A carotenoids (74.3% ß-carotene). Vitamin A intake was supplied by retinol (40%) and by provitamin A carotenoids (60%); vegetables contributed more than fruits (39.2% and 19.2%, respectively). Non-provitamin A carotenoid intake represents 43.9% of the total intake and is supplied by lycopene and lutein plus zeaxanthin in similar percentages (52.3% and 47.7%, respectively). CONCLUSIONS: The diet of these Dominican subjets met the recommended vitamin A intake, when expressed as retinol equivalents, 59% of which was supplied by provitamin-A carotenoids from plant sources, mainly by red/orange and white/yellow foods. Individual carotenoid intake is an aspect of great interest for issuing dietary recommendations in the public health setting.
Assuntos
Carotenoides/deficiência , Dieta , Sobrepeso/epidemiologia , Deficiência de Vitamina A/epidemiologia , Adulto , Idoso , Carotenoides/análise , República Dominicana/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Adulto JovemRESUMO
The aim of this research was to evaluate the effect of microwave or steam pre-treatment of raw sweet potato on physicochemical and microstructural properties, and the bioaccessibility of ß-carotene in sweet potato flour. This is the first report on using the in vitro digestion model suitable for food, as proposed in a consensus paper, to assess the bioaccessibility of ß-carotene in sweet potato flour. The pre-treatments produced a rearrangement of the flour matrix (starch, protein and non-starch polysaccharides), which was greater by using microwaves (M6) conducting to a greater increase in the phase transition temperatures up to 4.14 °C, while the enthalpy presented the higher reduction (4.49 J/g), both parameters in respect to the control. The resistant starch fraction was not modified, with about 3% in all samples. Microwave (M6) and all the steam pre-treatments showed the higher bioaccessibility of ß-carotene. This flour can be used in the development of new products with high ß-carotene content.