Functional Properties of Select Dry Bean Seeds and Flours

Select functional properties of 21 dry beans and soybean seeds and their corresponding flours were evaluated. Among the tested seeds, dark-red and light-red kidney beans had larger length (L)/breadth (B) ratios than the rest. Lentil seeds were the smallest (L/B = 0.98), thinnest (2.23 mm), and lightest (density 1.14 g/cm³ ) among the tested seeds. Garbanzo seeds were the thickest (thickness 7.05 mm). Highest bulk density (g/cm³ ), porosity (%), specific volume (cm³ /g), and bulk volume (cm³ /g) were registered, respectively, by moth bean (0.86 g/cm³ ), pink bean (66.53%), lentil (0.88 cm³ /g), and soybean (1.46 cm³ /g) seeds. Water uptake during soaking peaked in ≤12 hr by all bean seeds. Soybean and black bean flours, respectively, exhibited the highest water-holding (3.14 g/g) and oil-holding (2.15 g/g) capacities. Great Northern bean flour exhibited higher foaming volume (30.8% increase) than all the other tested seed flours. Stability of all bean flour foams were ≤36 hr. Black gram flour formed a gel at the lowest concentration (4% w/v) among all the tested seed flours. Garbanzo, soybean, tepary, and val bean flours failed to form a gel at ≤ 20% (w/v). The results indicate that the tested dry bean flours have great potential as functional ingredients for food formulations.

Understanding the functional properties of the dry bean seeds and flours is important for designing handling, transportation, storage, and processing methods for these beans and in guiding the selection of appropriate dry bean flours as food ingredients.