Black bean pasta meals with varying protein concentrations reduce postprandial glycemia and insulinemia similarly compared to white bread control in adults

Authors: WINHAM, DONNA - Iowa State University; THOMPSON, SHARON - University Of Illinois; HEER, MICHELLE - Iowa State University; DAVITT, ELIZABETH - Iowa State University; HOOPER, SHARON - Michigan State University; Cichy, Karen; KNOBLAUCH, SIMON - Iowa State University

Submitted to: Foods
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/26/2022
Publication Date: 6/3/2022
Citation: Winham, D.M., Thompson, S.V., Heer, M.M., Davitt, E.E., Hooper, S.D., Cichy, K.A., Knoblauch, S.T. 2022. Black bean pasta meals with varying protein concentrations reduce postprandial glycemia and insulinemia similarly compared to white bread control in adults. Foods. 11(11): Article 1652. https://doi.org/10.3390/foods11111652.
DOI: https://doi.org/10.3390/foods11111652

Interpretive Summary: The objective of this study was to determine the effect of three 100% black bean pastas made from differently processed flours on postprandial metabolic response, appetite measures, and gastrointestinal symptoms in normoglycemic adults in comparison to white bread and boiled whole black bean controls. The flour milling techniques were a standard process (Knife mill) and a novel milling method of compression/decompression (C/D mill) that produced flours with variable particle sizes and protein concentrations. 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. This finding is useful to the pulse milling industry, as currently there are no specifications for pulse flours regarding particle size or protein concentration.

Technical Abstract: Postprandial glycemic and insulinemic effects of three black bean pastas were evaluated among eighteen normoglycemic adults (8 men, 10 women) in a randomized cross-over 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-MP) were compared to two controls: whole black beans and white bread. Treatments contained 50g available carbohydrate. Plasma glucose, serum insulin, and appetite measures were collected at fasting and 30, 60, 90, 150, and 180 minutes postprandial. Gastrointestinal symptoms were evaluated 10-12 hours 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.