Abstract: In order to investigate the effect of concentration-induced sodium alginate gel on the gelatinization and retrogradation of rice starch, a system combining sodium alginate gelation and starch gelatinization was established by determining the preparation conditions of concentration-induced sodium alginate-Ca2+ gel and the addition of starch using rheological methods. water evaporation during heating triggered the transformation of sodium alginate (1 g/100 mL)-Ca2+ (3 mmol/L) system (storage modulus G’ < loss modulus G”) from a solution to a gel (G’ > G”) and the critical concentration of Ca2+ for gelling was 5.1 mmol/L. Sodium alginate-Ca2+ system containing 4–6 g/100 mL starch was converted from a liquid state (δ > 45°) to a solid-like state (δ < 45°) after water evaporation for 30 minutes with good preparation operability, which showed a closely linked network structure as seen under scanning electron microscope, accompanied by an increased G’ and a decreased flow index. These results confirmed that the alginate-Ca2+-starch system prepared under the above conditions could allow simultaneous sodium alginate gelation and starch gelatinization.

Key words: sodium alginate, gel, concentration-induced, rice starch, gelatinization