Submitted to: Starch/Starke
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/22/2004
Publication Date: 11/19/2004
Citation: Singh, N., Kaur, M., Sandhu, K., Guraya, H.S. 2004. Physico-chemical, thermal, morphological, and pasting properties of starches from some indian black gram (phaseolus mungo l.) varieties. Starch/Starke. 56(11):535-544. Interpretive Summary: Black gram is a pulse mainly grown and consumed in Asian countries, especially India. It is recommended as one of the few sources of carbohydrates for diabetics in herbal medicine. We wanted to find out what was unique about the starch. Therefore, we isolated starch from several black gram varieties, and conducted physical and chemical studies. We found that the black gram starch was high in a certain type of starch component, which make the starch probably less digestible. Breeding of higher amylose rice varieties is recommended to make starch which is more resistant to digestion.
Technical Abstract: The starches separated from thirteen different black gram varieties were investigated for physico-chemical, thermal, morphological, and rheological properties. Amylose content of starches from different black gram varieties ranged from 30.2-34.6%. The mean particle size of starch granules measured using laser light scattering particle size analyzer, varied from 12.77-14.34 um in all black gram starches. The transition temperatures and enthalpy of gelatinization were determined using Differential Scanning Calorimetry (DSC). UG-920 starch showed the lowest DHgel, while KU-3 starch showed the highest values. The starch separated from UG-562 showed lower transition temperatures (To, Tp and Tc) than the starch from UG-909. Pasting properties of starches from different black gram varieties, measured using Rapid visco-analyzer, also differed significantly. The starch from UG-909 showed the highest pasting temperature, whereas, UG-562 starch showed the lowest value for the same. Turbidity values of gelatinized paste from all black gram starches progressively increased during refrigerated storage. UG-1017 starch paste showed the lowest turbidity value and UG-902 showed the highest value.