Consumo de fibras alimentares em população adulta Dietary fiber consumption in an adult population

OBJETIVO: As fibras alimentares estão entre os principais fatores da alimentação na prevenção de doenças crônicas. Por isso, objetivou-se estimar o consumo médio diário de fibras alimentares totais, insolúveis e solúveis, nas refeições de uma população de área metropolitana. MÉTODOS: Foi estudada uma amostra da população do Município de Cotia, SP, composta por 559 indivíduos com mais de 20 anos. O consumo alimentar foi obtido pelo método de história alimentar - dieta habitual. Foram identificadas as fontes de fibras nas refeições: desjejum, almoço e jantar. Com base na porção média, os alimentos foram classificados quanto ao conteúdo de fibras como: muito alto (7 g ou mais); alto (4,5 g a 6,9 g); moderado (2,4 g a 4,4 g) e baixo (< 2,4 g). RESULTADOS: O consumo médio diário da população foi de 24 g de fibras totais, sendo as quantidades médias de fibras insolúveis 17 g e, de solúveis, 7 g. O consumo de fibras alimentares entre mulheres e homens foi, respectivamente, 20 g e 29 g (p<0,01). A maioria dos alimentos presentes na dieta continha baixo teor de fibras. O feijão foi o único alimento com alto teor de fibras na dieta habitual e, a principal fonte de fibra na alimentação. O almoço e o jantar foram as refeições que forneceram maior quantidade de fibras. CONCLUSÕES: Constatou-se baixo consumo de fibras alimentares, com diferenças estatisticamente significante entre os sexos. As práticas alimentares revelaram que a dieta é constituída por alimentos pobres em fibras alimentares.<br>OBJECTIVE: The dietary fiber has emerged as a leading dietary factor in the prevention and treatment of chronic diseases. I was estimated the average consumption of total dietary fiber (DF), insoluble fiber (IF) and soluble fiber (SF) in the meals of both sex adults from the town of Cotia, a metropolitan area in S. Paulo State, Brazil. METHODS: A population sample of Cotia country, S. Paulo (Brazil), consisted of 559 adults older than 20 years old, was studied. Food consumption was assessed by the dietary history habits. The amount of dietary fiber in each meal (breakfast, lunch and diner) was estimated by the serving size. The foods were classified according to their fiber content in Very High (7 g or more), High (4.5 to 6.9), Moderate (2.4 to 4.4) and Low (<2.4). RESULTS: The average population's consumption of dietary fiber was of 24 g/day, with an average consumption of insoluble fiber of 17 g/day and soluble of 7 g/day. Among women, the average consumption was 20 g/day and among men 29 g/day (p<0.01). Most of the foods in their diet were classified as having a low content of dietary fiber. Beans were the most important dietary fiber source in the population diet. Lunch and diner were the meal with a higher content of dietary fiber. CONCLUSIONS: A low consumption of dietary fiber in the population sample could be detected. Their usual sources of dietary fiber were poor

Determining the polysaccharide composition of plant cell walls

The plant cell wall is a chemically complex structure composed mostly of polysaccharides. Detailed analyses of these cell wall polysaccharides are essential for our understanding of plant development and for our use of plant biomass (largely wall material) in the food, agriculture, fabric, timber, biofuel and biocomposite industries. We present analytical techniques not only to define the fine chemical structures of individual cell wall polysaccharides but also to estimate the overall polysaccharide composition of cell wall preparations. The procedure covers the preparation of cell walls, together with gas chromatography–mass spectrometry (GC-MS)-based methods, for both the analysis of monosaccharides as their volatile alditol acetate derivatives and for methylation analysis to determine linkage positions between monosaccharide residues as their volatile partially methylated alditol acetate derivatives. Analysis time will vary depending on both the method used and the tissue type, and ranges from 2 d for a simple neutral sugar composition to 2 weeks for a carboxyl reduction/methylation linkage analysis.Filomena A Pettolino, Cherie Walsh, Geoffrey B Fincher & Antony Baci