Maize and resistant starch enriched breads reduce postprandial glycemic responses in rats

Area of Science:

• Food Science and Technology
• Nutritional Biochemistry
• Metabolic Health

Background:

• White wheat bread offers limited dietary fiber, creating a need for breads with improved glycemic control.
• Slowly digestible or resistant starch (RS) incorporation aims to reduce glucose absorption and lower bread's glycemic index.
• Maize flour and RS are explored for their potential to enhance metabolic health benefits in bread.

Purpose of the Study:

• To investigate the metabolic effects of Portuguese maize bread versus white wheat bread in rats.
• To evaluate the impact of resistant starch (RS) on glycemic response in both wheat and maize bread formulations.
• To assess how different bread formulations and processing affect the metabolic benefits of RS.

Main Methods:

• Male Wistar rats (n=36) were divided into four groups, fed wheat bread, RS-wheat bread, maize bread, or RS-maize bread.
• Resistant starch (RS) was incorporated at 20% of flour inclusion in wheat and maize bread formulations.
• Evaluated parameters included feed intake, body weight gain, fecal pH, postprandial blood glucose, triglycerides, total cholesterol, and liver weight.

Main Results:

• Maize bread consumption led to higher body weight gain and cholesterol, lower fecal pH, and reduced postprandial blood glucose compared to wheat bread.
• RS-wheat bread significantly decreased feed intake, fecal pH, postprandial blood glucose response, and total cholesterol.
• RS-maize bread showed reductions in body weight gain, fecal pH, and total cholesterol, with only a fasting glucose reduction observed.

Conclusions:

• Maize bread exhibits a lower glycemic index than traditional wheat bread.
• The effectiveness of resistant starch in modulating glycemic response is dependent on the type of bread (wheat vs. maize).
• Incorporating RS into wheat bread offers significant metabolic advantages, while its impact on glycemic response in maize bread requires further investigation.