Instituto Nacional dos Recursos Biológicos, IP, L-INIA, Unidade Tecnologia Alimentar, Av da República, 2784-505 Oeiras, Portugal.
Nutr Res. 2011 Apr;31(4):302-8. doi: 10.1016/j.nutres.2011.02.001. Epub 2011 Mar 22.
White wheat bread is a poor source of dietary fiber, typically containing less than 2%. A demand exists for the development of breads with starch that is slowly digestible or partially resistant to the digestive process. The utilization of maize flour and resistant starch is expected to reduce the release and absorption of glucose and, hence, lower the glycemic index of bread. This study was undertaken to investigate the hypothesis that a diet of maize bread, as produced and consumed in Portugal, would have beneficial metabolic effects on rats compared to white wheat bread. We also hypothesized that the effect of resistant starch on glycemic response could be altered by the use of different formulations and breadmaking processes for wheat and maize breads. Resistant starch (RS) was incorporated into formulations of breads at 20% of the inclusion rate of wheat and maize flours. Assays were conducted with male Wistar rats (n = 36), divided into four groups and fed either wheat bread, RS-wheat bread, maize bread, and RS-maize bread to evaluate feed intake, body weight gain, fecal pH, and postprandial blood glucose response (glycemic response). Blood triglycerides, total cholesterol concentrations, and liver weights were also determined. The maize bread group presented higher body weight gain and cholesterol level, lower fecal pH, and postprandial blood glucose response than the wheat bread group. The RS-wheat bread group showed significant reductions in feed intake, fecal pH, postprandial blood glucose response, and total cholesterol. The RS-maize group displayed significant reductions of body weight gain, fecal pH, and total cholesterol levels; however, for the glycemic response, only a reduction in fasting level was observed. These results suggest that maize bread has a lower glycemic index than wheat bread, and the magnitude of the effect of RS on glycemic response depends of type of bread.
白小麦面包膳食纤维含量低，通常低于 2%。因此，人们需要开发出淀粉消化缓慢或部分抗消化的面包。利用玉米粉和抗性淀粉有望减少葡萄糖的释放和吸收，从而降低面包的血糖生成指数。本研究旨在验证以下假设：与白小麦面包相比，葡萄牙生产和消费的玉米面包对大鼠具有有益的代谢作用。我们还假设，抗性淀粉对血糖反应的影响可能因小麦和玉米面包的不同配方和面包制作工艺而改变。抗性淀粉（RS）以 20%的小麦和玉米粉添加量添加到面包配方中。用雄性 Wistar 大鼠（n = 36）进行试验，将大鼠分为四组，分别喂食小麦面包、RS-小麦面包、玉米面包和 RS-玉米面包，以评估采食量、体重增加、粪便 pH 值和餐后血糖反应（血糖反应）。还测定了血甘油三酯、总胆固醇浓度和肝重。与小麦面包组相比，玉米面包组的体重增加和胆固醇水平较高，粪便 pH 值和餐后血糖反应较低。RS-小麦面包组的采食量、粪便 pH 值、餐后血糖反应和总胆固醇均显著降低。RS-玉米组的体重增加、粪便 pH 值和总胆固醇水平显著降低；然而，对于血糖反应，仅观察到空腹水平降低。这些结果表明，玉米面包的血糖生成指数低于小麦面包，RS 对血糖反应的影响程度取决于面包的类型。
