ARS | Publication request: Physicochemical, Thermal, Morphological, and Pasting Properties of Starches from Some Indian Black Gram (Phaseolus mungo L.) Cultivars.

Submitted to: Starch/Starke
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 28, 2004
Publication Date: November 12, 2004
Citation: Singh, N., Kaur, M., Sandhu, K., Guraya, H.S. 2004. Physicochemical, thermal, morphological, and pasting properties of starches from some indian black gram (phaseolus mungo L.) cultivars. Starch/Starke. 56(11):535-544.

Interpretive Summary: Black Gram is a very important bean in the diet of vegetarian Indians, since it is composed of 26% protein. It is now widely cultivated and used in the tropics. The bean is used whole, husked, sprouted, or ground into flour, which when combined with rice flour is especially valued in baking. It accounts for 40% of total pulse production in India, but it still falls short. Australia has started breeding programs for Indian Black Gram for export to India and other countries. With the increasing Asian population in the United States, Black Gram is currently being imported. Opportunities exit for American farmers to grow this crop for export and domestic consumption. We surveyed various varieties of Indian Black Gram to determine their functional properties for use in various food products.

Technical Abstract: Starches from 13 different Black Gram cultivars were investigated for physicochemical, thermal, morphological, and pasting properties. Amylose content, swelling power, solubility, and water binding capacity of starches were 30.2-34.6%, 16.0-22.3 g/g, 14.8-17.3%, and 73.5-84.5%, respectively. The diameter of starch granules, measured using a laser-light scattering particle-size analyser, varied from 12.8 to 14.3 micrometer in all Black Gram starches. The shape of starch granules varied from oval to elliptical. The transition temperature (To, Tp, and Tc) determined using DSC, were in the ranges 66.1-71.3, 71.0-76.2, and 75.9-80.4°C, respectively, and the gelatinization enthalpy was 6.7-9.4 J/g. Pasting properties of starches measured using the Rapid Visco Analyser (RVA) also differed significantly. Pasting temperature, peak viscosity, trough, breakdown, final viscosity, and setback were in the ranges 75.8-80.3°C, 422-514 Rapid Visco Units (RVU), 180-311 RVU, 134-212 RVU, 400-439 RVU, and 102-151 RVU, respectively. Turbidity values of gelatinized starch pastes increased during refrigerated storage. The relationships between different properties were also determined using Pearson Correlation Coeff. Amylose contents showed a positive correlation with swelling power, turbidity, and granule diameter. Swelling power showed a negative correlation with solubility and setback. To, Tp, and Tc showed positive correlations with turbidity and pasting temperature, but were negatively correlated with peak and breakdown viscosity.