Six dietary fiber sources, wheat bran, corn bran, soy bran, oat hulls, rice bran, and cellulose were examined with regard to their abilities to bind copper, zinc, and iron. Their chemical composition, some of their physical properties, and their in vivo action on mineral status in tissues of chicks were investigated. Also, a comparison of the physicochemical properties of neutral detergent treated (NDF) and pepsin-pancreatin treated (EIR) residues was made. The release of endogenous copper, zinc, and iron from the fiber sources was pH dependent. Greater amounts of minerals were released into solution at pH 0.65 than into solution at pH 6.8. After a sequential treatment of pH 0.65 solution, neutralization, then pH 6.8 buffer, the mineral levels in the residues were similar to those remaining in the residues after the near neutral treatment. This indicated that the minerals were rebound after the pH of the solution was raised from acidic to near neutral. The amount of zinc in the residues from the sequential treatment correlated positively to protein and phytic acid contents and negatively to NDF and EIR contents. Neither copper nor iron showed any significant correlations. Hydrogen ion buffering capacities were determined for three preparations of the six fiber sources: (1) untreated, original material; (2) NDF-treated; and (3) EIR-treated materials. The buffering capacities were expressed as functions of the slopes of titration curves, where the smaller the slope, the greater the buffering capacity. The treated preparations had lower buffering capacities than did the untreated preparation. The treatments reduced the amounts of digestible/soluble components, especially protein in the fiber sources. Protein content was strongly correlated to buffering capacity for the untreated and the EIR-treated preparations but not for the NDF-treated preparation. Wheat bran, soy bran, oat hulls, and cellulose were subjected to NDF and EIR treatments, and the residues were used as column material for cation exchange experiments. A factorial experiment was performed using fibers by treatments by three solutions. The solutions were copper alone, zinc alone, and copper-zinc in combination. Cation exchange capacities (CEC) and protein contents were also determined. The CEC values for the residues from the two treatments for wheat bran and cellulose were similar but were very different for the soy bran (EIR-treated CEC was higher than NDF-treated) and oat hulls (NDF much greater than EIR). More mmoles of copper were bound than zinc whether presented alone or in equimolar combination. Protein content correlated to mmoles mineral bound for only the NDF-treated residues and only when the minerals were presented singly. These in vitro experiments demonstrated the intrinsic differences of the fiber sources. One fiber source may be beneficial to nutritional status while another may be detrimental. The fiber isolation technique produced residues with different compositions and different physical properties. Future biochemical investigations of dietary fiber must acknowledge the possible divergence from physiological reality which results from the isolation methodology. The chick feeding study used diets which had the fiber sources added to be equivalent to the addition of 6% dietary fiber (as NDF). At this level, all the fiber sources, except rice bran, resulted in adequate growth and adequate deposition of tissue minerals. The chicks on the rice bran diet had lowered feed intakes, significantly reduced growth and significantly lower tibia zinc, iron, and manganese levels. One factor in the rice bran diet, which may have influenced the status of the chicks, was its phytic acid content which was the highest of the fiber sources. This in vivo experiment again indicates the dissimilarity in effects of the dietary fiber sources.

In an attempt to determine the relationship between dietary fiber and estrogen levels in premenopausal adult women, seven subjects completed all of the requirements as volunteers for this study. The subjects consumed two experimental diets using a cross-over experimental design. One-half of the subjects were randomly assigned to a low-fiber treatment group and one-half were assigned to a high-fiber treatment group. Food records were utilized to determine fiber intake throughout the study. Nutrient intake during the experimental periods demonstrated significant differences indicating the affect of the varied dietary regimens. No significant difference was seen in mean estrogen levels between the low- and high-fiber experimental periods, however, a positive significant correlation (p<.05) was observed with the change in estrogen level and insoluble fiber intake. Further study with a larger subject sample would be beneficial in determining recommendations for amounts of insoluble fiber intake for the general population. / Department of Family and Consumer Sciences

Thesis (doctoral)--Lund University, 1994. / Added t.p. with thesis statement inserted.

Thesis (doctoral)--Lund University, 1994. / Added t.p. with thesis statement inserted.

Thesis, PlanA (M.S.)--University of Wisconsin--Stout, 2006. / Includes bibliographical references.

The effect of a diet including cooked pinto beans on plasma total cholesterol in hamsters was investigated. The legume diet had 8.1% total fiber (1.0% soluble, 7.1% insoluble), all from pinto beans. Animals initially consumed a hypercholesterolemia-inducing diet. One control group remained on this feed for the duration of the study, and another consumed a diet with 8.6% total fiber (cellulose). The pinto bean diet lowered plasma cholesterol significantly (13%) only in hypercholesterolemic hamsters (approximately 75% of the animals). When all animals were considered, the legume diet had no effect on cholesterol. Variability among hamsters in plasma cholesterol levels and changes was large. Results indicate the importance of including only hypercholesterolemic animals in studies of dietary modifications to decrease blood cholesterol and also that a large sample size may be required to detect significant effects. Soluble and insoluble dietary fiber in raw and cooked carrots were measured by a typical enzymatic-gravimetric procedure. Analyses were done with and without freeze-drying and the starch gelatinization treatment (heating 1.25 hrs at 121°C). The gelatinization procedure caused a 3- to 5-fold increase in soluble fiber. In general, insoluble fiber decreased in the same proportion as the soluble fraction increased, suggesting a conversion of the former to the latter. The differences were greatest for cooked carrots and freeze-dried raw carrots. Compositional analyses indicated that heating increased arabinose, galactose, and uronic acids in soluble fiber fractions. Cooked carrots had 3-9% more soluble fiber than raw carrots, with the difference being greater when the analysis included the gelatinization procedure. However, freeze-dried raw samples analyzed with gelatinization had the same level of soluble fiber (ca. 10%) as their boiled counterpart, suggesting an interaction between freeze-drying and the heat treatment in raw carrots. Freeze-drying and heating to gelatinize starch are an integral part of many standard dietary fiber methods. Results of the present study suggest these treatments may mask differences between the amount of fiber in cooked and raw foods, and that dietary fiber values may not accurately represent the level of this component in foods as they are eaten. The results also raise the possibility of increasing soluble fiber by cooking modifications. / Ph. D.

Forty Sprague Dawley rats were randomly placed in five groups with eight rats per group. Each group varied in dietary composition for fiber type and carbohydrate source. Groups one and two received oat fiber and either sucrose or corn starch as the carbohydrate source. Groups three and four received corn bran as the fiber source and either sucrose or corn starch as the carbohydrate source. Group five (considered the control group), received Purina standard rat chow. Analysis of variance showed only significant differences for food intake, and the control group had a significantly higher food intake. Weight gain, serum cholesterol and triglyceride levels showed no significant differences.

published_or_final_version / Zoology / Master / Master of Philosophy

This research project investigated a method to promote one low-fat, high-fiber choice in a national chain fast-food restaurant. It is an extension of efforts toward large-scale dietary change. A procedural extension of a prompting strategy was used in an attempt to influence customers to choose a salad. A simple visual and print message based on themes derived from formative and pilot research at the restaurant was presented during two intervention phases of a reversal design. The message, "Be Fit and Healthy; Eat a Low-fat SALAD as Your Meal or Add a Side Salad," was displayed in colorful posters and tent cards which were placed on all the tables. Data from a comparison base in a neighboring town were obtained. A one-month follow-up phase was included in the design. Prices and in-store advertisements were identical in both locations. The existing computerized cash register system was used to obtain accurate, objective data. Daily and weekly sales percentages of several entrees were obtained. Results of analysis using a correction procedure indicate that when graphically represented, salad sales across phases increased with the introduction of the prompts, and decreased with their removal. In addition, three entrees not represented by associated prompts remained stable across phases. For Salads-combined, results indicate that sales increased about 15% and 9%, respectively, for the first and second intervention phases. Daily temperature during this project was variable. Although a comparison site was used to control for the effects of weather, results indicate that salad prompting may have increased sales more during warmer temperature. Population demographics were recorded. Analyses of the customer population during this project indicate customers were about equal by gender, and consisted primarily of white, 18-39 years old individuals. The cost for each added salad bought during the intervention was about $.22, and the cost to raise the percent of salad sales, each percent, across the four weeks was about $16.00. Future research should attempt to foster longer term behavior change and integrate multifaceted promotions. / Master of Science

The absorption of free carbohydrates produced by digestion of dietary fiber in monogastric animals was investigated. Previous studies have shown that dietary fiber is partially digested by monogastric animals in its passage through the alimentary canal. However, the ability of monogastric animals to absorb the products of digestion of dietary fiber is uncertain. Male rats of the Sprague-Dawley strain were fed a refined carbohydrate diet in which sucrose comprised 66.6 percent. The urine of rats fed this diet contained only sucrose and its component monosaccharides, glucose and fructose, indicating that the carbohydrate composition of urine reflects the carbohydrate composition of the diet. The rats were then fed diets containing 5 percent guar gum (a galactomannan), 10 percent xylan (a polymer of xylose), or 10 percent wheat bran. The appearance in the urine of the component carbohydrates of the ingested dietary fiber was used as an indication of the absorption of the carbohydrates derived from fiber digestion. The urine of rats fed guar gum contained galactose. Rats fed xylan excreted xylose in the urine. Xylose and arabinose were identified in the urine of rats fed wheat bran. It is postulated that the polysaccharides of dietary fiber are degraded to simple sugars by bacteria in the colon. The results of this study indicate that free carbohydrates produced by digestion of dietary fiber are absorbed in monogastric animals. The potential nutritional and toxicological effects of the absorption of the carbohydrate components of dietary fiber are discussed. / Master of Science