Relationship between the Thermal Denaturation and Gelling Properties of Legumin from Broad Beans

The effects of NaCl and heating temperature on the gel-forming ability of legumin were studied. The addition of NaCl progressively increased the denaturation temperature of legumin. Heating to around the denaturation point, i.e., below the onset temperature (zone 1), between the onset and maximal temperatures (zone 2), between the maximal and final temperatures (zone 3), and above the final temperature (zone 4), affected both the gel-forming ability and gel properties. No gel was formed in zone 1, while the gel was harder in zone 3 than in zones 2 and 4. The gel hardness gradually decreased with increasing temperature in zone 4. Differences in the viscoelastic and microstructural properties between gels heated at various temperatures around the denaturation point were observed.