Master of Science (MS)
The purpose of this study was to calculate the metabolizable energy value of Hi-Maize® RS (60% amylose), to observe if consumption of RS alters adiposity, and to examine the effects of RS on fermentation and fecal excretion. Eighteen four-week old male Sprague-Dawley rats consumed either a 20% amylose Hi-Maize® RS diet (n=6) or a control diet (baseline group, n=6; control group, n=6). The baseline group was sacrificed at the beginning of the study; the RS and control groups were transferred to metabolic cages and fed the respective diets for the next six weeks. Feces and urine from each individual rat was collected daily and stored separately for each of the periods. At sacrifice, fat pads were weighed; gastrointestinal tract organs were cleaned and weighed. Baseline rat data were used to determine the total energy gained in RS and control rats. Metabolizable energy value of Hi-Maize® RS was determined by a calculation by Livesey (1995) using energy data from bomb calorimetry of the diet, urine and feces. At the end of the third period, the metabolizable energy value for Hi-Maize® RS was 1.55 kcal/g. The value for the RS diet was 3.66 kcal/g, which was significantly lower than the control diet of 4.29 kcal/g (p < 0.001). Adaptation to the RS diet occurred over time as seen by changes in the digestible energy values of RS per each period. For the RS group, abdominal fat was lower (p < 0.05) possibly due to lower metabolizable energy of the RS diet, cecum and large intestine weights were greater (p < 0.001), and pH of the cecal contents was lower than the control rats (p < 0.001) due to greater fermentation of the RS diet. Fecal weight for each of the periods was greater in the RS group (p < 0.001) compared to the control group. Compared to the consumption of a highly digestible starch diet, Hi-Maize ® RS provides less energy to the body and increases fermentation and fecal excretion, which may provide a healthier colonic environment.
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Garcia, Tanya A., "The metabolizable energy value and physiologic effects of Hi-Maize resistant starch in male rats" (2003). LSU Master's Theses. 2972.