Avaliação de efeitos fisiológicos da fração fibra alimentar dos grãos de amaranto (Amaranthus cruentus L.) e linhaça (Linum usitatissimun L). / Evaluation of dietary fiber physiological effects of amaranth (Amaranthus cruentus) and flaxseed (Linum usitatissimum L.) grains.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The flaxseed and amaranth grains are recognized by their nutritional and functional health attributes. These grains have significant contents of dietary fiber (28 and 10%, respectively), and the physiological effects related to these fractions were investigated by colonic fermentative and lipid metabolism parameters with rats (Wistar) distributed in five groups (n=12) during twenty-eight days. The diets of the Reference and Control groups contained 7% (w/w) of cellulose and the diets of the experimental groups were formulated with: defatted flaxseed flour and defatted extruded amaranth, in order to provide 7% dietary fiber (DF). With the exception of the Reference, the other diets received 0,5% cholesterol. The Flaxseed and Amaranth groups compared to the Control showed: greater weight of caecum and its contents; greater weight of feces (wet mass); increase of short chain fatty acids (SCFA) concentration and decrease of pH of cecal content, indicating colonic fermentation. The Flaxseed group showed lower liver hepatic weight and cholesterol, but no changes in plasmatic cholesterol, cholesterol fecal excretion, or bile acids fecal excretion. The Amaranth group exhibited lesser hepatic weight, along with no changes on hepatic cholesterol. Also, no plasma cholesterol reduction was observed, with the increase of fecal cholesterol excretion and decrease in fecal bile acid excretion. It is suggest that the caecum wall trophism was related to butiric acid production, main energy colonic cell substrate that fosters a more resistant mucosa to pathogens and carcinogens. The mechanism involved in liver protecting effect, observed in the Flaxseed group, could be related to propionic acid production, since that it is suggest in the literature that this fatty acid could be envolved in the HMG-CoA reductase inhibition. Until this moment, the mechanisms that promoted the lesser bile acid excretion by the Amaranth group were not kwon. The DFs of flaxseed and amaranth grains were unable to promote hypocholestelolemic effects under the present assay conditions. It could be concluded that DFs of flaxseed and amaranth grains are beneficial to the health of the intestinal mucosa.

ASSUNTO(S)

acidos graxos de cadeia curta intestinal mucosa mucosa intestinal short chain fatty acids lipidic metabolism metabolismo lipídico fermentation fermentação

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