Functional Properties of Modified Black Gram (Phaseolus mungo L.) Starch

Black gram (Phaseolus mungo L.) starch was modified by heat and moisture treatments, acetylation, oxidation, cross-linking, and adding free fatty acids (palmitic, stearic, and linoleic). Heat and low moisture treatment, acetylation, oxidation, and cross-linking lowered the starch gelatinization temperature by 1–6°C, while adding fatty acids and the high moisture-heat treatment raised it by 1–4°C. All modifications caused an increase in least gelation concentration of starch. High moisture-heat treatment increased both water and oil absorption of starch. At 95°C, heat-moisture treated, acetylated, and oxidized starches were more soluble, while fatty acid treated and cross-linked starches were less soluble compared to raw starch. The modified starches had greater swelling capacity and solubility at pH 2.0 and 10.0. Heat-moisture treated and chemically modified starches had lower swelling capacity (at 95°C) than that of isolated starch, whereas addition of fatty acids increased it.