Cereal Chem 67:390-394 | VIEW
Functional Properties of Pin-Milled and Air-Classified Dry Edible Bean Fractions.
J.-Y. Han and K. Khan. Copyright 1990 by the American Association of Cereal Chemists, Inc.
The functional properties of fractions separated by pin-milling and air classification of legumes were affected by heat treatment (roasting) of the legumes, the ratio of protein to starch in the fractions, and other constituents, such as the lipid content in the original legume samples. Nitrogen solubility index and foaming properties decreased as roasting temperature increased, most likely due to protein denaturation. Also, roasting resulted in increased water-holding capacity and cold paste viscosities. Cold paste viscosities of fractions from roasted legumes were notably higher than those from the nonroasted legumes. The starch-rich fractions showed the strongest water-holding capacity, nitrogen solubility, and cold paste viscosity, whereas the protein-rich fractions were duperior in emulsification and foamability. Differences in functionality between the protein and starch fractions were not large in chick-pea, which exhibited poor starch and protein separation compared with pinto and navy beans. Although there were significant variations in some of the functional properties of each fraction with heat treatment, each food system may require fractions with different functional properties depending on the purpose. Therefore, it is not appropriate to say that a certain legume or air-classified fraction is more or less desirable.