33G-29 |
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K. D. RABB1, T. A. Garcia, A. R. Francis, M. J. Keenan, K. L. McCutcheon, and M. Hegsted. (1) School of Human Ecology, Louisiana State Univ. Agricultural Center, PO Box 25100, Baton Rouge, LA 70803 Resistant starch (RS) resists digestion in the small intestine. The undigested starch passes into the large intestine where it is fermented by intestinal bacteria into short chain fatty acids that lower the pH in the large intestine and may increase mineral absorption. Other benefits of RS include, increasing fecal bulk, decreasing fecal transit time, and providing butyric acid for colonic health. The purpose of this study is to measure the amount of mineral absorption in rats fed an amylose RS (Hi-MaizeŽ, National Starch) diet as compared to rats fed a control (C) diet. Twelve 4-week old male Sprague-Dawley rats were fed either a RS diet (n=6, 20% amylose) or a C diet (n=6, 0% amylose) for 6 weeks. Fecal output was collected and pooled into three 2-week metabolic periods. Feces and diet were microwave digested and analyzed by inductively coupled plasma spectrophotometry to determine the mineral absorption in each period. The RS rats had greater wet and dry fecal weight output for all three periods (p<0.001), but similar food intakes. In Period 1 the RS diet decreased percent absorption for Cu, Fe, Mg, Mn, N, P, K, Na, and Zn. In Period 2 the percent absorption for RS rats was lower for the same minerals except Mg. RS rats in Period 3 had lower percent absorption for Fe, Mn, N, P, K, and Na but not Cu or Zn. Mg absorption was increased by RS in period 3. Ca absorption was not affected by RS. RS either decreased or had no effect on mineral absorption except for increased Mg absorption in period 3. The lower absorption found in RS fed rats was possibly due to greater fecal output. Thus improvement of mineral absorption is not one of the health benefits of RS in the diet.
Session 33G, Nutraceuticals & Functional Foods: Lipid and probiotic functional foods
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