Gelation properties of chickpea protein isolates

The effects of pH, sodium and calcium chloride on the gelation properties of chickpea protein isolates (CPI) were investigated. The dispersion prepared with deionized water at pH 3.0 behaved as diluted solution, while dispersions at pH 3.0 with 0.1 M NaCl and pH 7.0 with 0.5–1.0 M NaCl behaved as semidiluted solutions. The samples prepared with high ionic strengths (0.5–1.0 M NaCl) at pH 3.0 and with low ionic strengths (0–0.1 M NaCl) at pH 7.0 were more elastic with a gel-like behavior. The samples at pH 3.0 with high ionic strengths and at pH 7.0 with low ionic strengths had the similar gelation kinetics. The effect of calcium chloride on gelation properties of CPI was similar to that of NaCl. The dispersions behaved as gel at pH 3.0, CaCl2 0.1–0.3 M and pH 7.0, CaCl2 0.1 M, because they were more elastic than viscous. The sample at pH 7.0 with 0.3 M CaCl2 behaved as semidiluted solutions. The gel strength at pH 3.0, 0.1 and 0.3 M CaCl2 was 24 and 26.4 g, respectively. However, the gel strength prepared with 0.1, 0.5 and 1.0 M NaCl was 7.6, 8.4 and 9.3 g, respectively.