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ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Functional Foods Research » Research » Publications at this Location » Publication #378006

Research Project: Improved Utilization of Whole Pulses, Pulse Fractions, and Pulse Byproducts for Health-Promoting Food Ingredients and Biobased Products

Location: Functional Foods Research

Title: Effect of particle size and processing method on starch and protein digestibility of navy bean flour

item Byars, Jeffrey
item Singh, Mukti
item Kenar, James - Jim
item Felker, Frederick
item Moser, Jill

Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/4/2021
Publication Date: 3/7/2021
Citation: Byars, J.A., Singh, M., Kenar, J.A., Felker, F.C., Moser, J.K. 2021. Effect of particle size and processing method on starch and protein digestibility of navy bean flour. Cereal Chemistry. 98(4):829-839.

Interpretive Summary: This research determined that the amount of protein that can be digested from cooked navy bean flour depends on the particle size of the flour. It was previously known that particle size affects starch digestion, but this is the first study on protein digestibility for navy bean flours of different particles sizes. The in vitro digestibility of protein decreased with increasing particle size. The digestibility also depended on the heating method with cooking > baking > roasting. These findings are important since it shows that product formulators should consider nutrient availability when selecting pulse flours.

Technical Abstract: Background and objectives: Intact cotyledon cells in pulses are known to limit the access of digestive enzymes and to decrease starch digestibility. The objective of this study was to study the effect of the cells on protein digestibility and raffinose family oligosaccharide (RFO) extraction. The in vitro starch and protein digestion and RFO extraction was studied for roasted, baked and cooked navy bean flour fractions with large (297-500 mm), medium (74-297 mm) and small (< 74 mm) particle sizes. Findings: The starch and protein digestibility were highest for the smallest particle size flour. The digestibility was lowest for roasted flours and highest for cooked flours. Intact cotyledon cells did not affect RFO extraction. Conclusions: The in vitro protein digestibility increased with decreasing particle size for three fractions of navy bean flour that had been roasted, baked or cooked. Significance and novelty: This is the first study showing that navy bean flours with different particle sizes have different in vitro protein digestibility. The effect on nutrient availability should be considered when selecting pulse flours for food applications.