Black Bean Pasta Meals with Varying Protein Concentrations Reduce Postprandial Glycemia and Insulinemia Similarly Compared to White Bread Control in Adults

Postprandial glycemic and insulinemic effects of three black bean pastas were evaluated among eighteen normoglycemic adults (8 men, 10 women) in a randomized crossover trial. Black beans were milled into flour using a commercial Knife or compression/decompression mill (C/D mill). The C/D-mill-derived pastas had medium protein (Combo-MP) and low protein (Cyclone-LP) concentrations. Three black bean flour pastas (Knife, Combo-MP, and Cyclone-LP) were compared to two controls: white bread and whole black beans. Treatments contained 50 g of available carbohydrate. Plasma glucose, serum insulin, and appetite measures were collected at fasting and 30, 60, 90, 150, and 180 min postprandial. Gastrointestinal symptoms were evaluated 10-12 h postprandial. ANOVA (one-way, repeated measures) was used to evaluate satiety, gastrointestinal symptoms, sensory variables, glucose and insulin differences from baseline, and incremental area under the curve (iAUC) by time and/or treatment. Three-hour glucose and insulin iAUCs were lower with whole black beans than white bread. Black bean pasta meals increased satiety, reduced appetite, and produced numerically lower glucose and insulin responses than white bread. However, no differences were observed between pasta types, indicating a similar metabolic response regardless of milling technique. Our results provide evidence for dietary guidance to reduce postprandial glucose and related health risks through pulse food products.