Analysis of foodstuffs for dietary fiber by the urea enzymatic dialysis method.

Total dietary fiber (TDF) values for cereal grains, fruits, vegetables, processed foods, and purified or semi-purified dietary fiber products were determined by a new method using 8M urea and enzymes (urea enzymatic dialysis, UED, method). The results are compared with the official AOAC procedure. Soluble and insoluble dietary fiber were determined for several of these foodstuffs and compared with the NDF values.

Improved methods for analysis and biological characterization of fiber.

Dietary fibers are not uniform, chemically or in their nutritive and biological properties, the only common ground being their resistance to mammalian digestive enzymes. The AOAC method for total fiber is subject to inferences from ash, protein, tannins and resistant starches. These interferences can be reduced by urea enzymatic dialysis.

Urea enzymatic dialysis procedure for determination of total dietary fiber.

A method that uses urea and enzymes for determination of total dietary fiber (TDF) in foods has been developed and compared with the AOAC enzymatic-gravimetric method (43.A14-43.A20).

Colonic carcinogenesis: the microbial feast or famine mechanism.

A mechanism is presented which suggests that high-fat, high-protein, low-fiber diets can cause an unfavorable microbial environment in the human colon which predisposes some individuals towards large bowel diseases. The digesta leaving the ileum on high-fat, high-protein, low-fiber diets has a high proportion of mucins, malabsorbed carbohydrates and proteins, bile acids, and sloughed epithelial cells. The irregular (pulsatile) emptying of rapidly fermentable ileal digesta into the colon causes a massive surge in microbial activity.

Effect of in vitro fermentation using human faecal inoculum on the water-holding capacity of dietary fibre.

The water-holding capacities (WHC) of four sources of fibre were measured using dialysis membranes and osmotic-suction pressures of 45, 89 and 178 mosmol/1 (1, 2 and 4 atm). At all pressures, pectin had the highest WHC, followed by cabbage (Brassica oleracea) and lucerne (Medicago sativa) and then cellulose. A suction pressure of 89 mosmol/1 (2 atm) was used in the subsequent fermentation study since it had the lowest standard error of the mean and most closely approximated physiological conditions.