Effect of whole chia seed flour on gelling properties, microstructure and texture modification of tofu

Abstract

Effect of whole chia seed flour (WCSF) on the gelation, microstructure, texture, and water-binding ability of tofu was studied. The WCSF with different concentration (1.0, 1.5 and 2.0% w/w) was added in soymilk. Glucono-δ-lactone (GDL) was used as coagulant for tofu making. Results showed that the initial gelling time of soymilk gradually decreased with the increase of WCSF concentration, but it did not affect the gelling rate of soymilk during gelation. The tanδ of chia seed tofu was between 0.154 and 0.166, indicating a weak gel structure. Control tofu showed a continuous and honeycomb-like structure, whereas tofu with 2% (w/w) WCSF had a discontinuous network. Furthermore, the addition of WCSF decreased the texture property and increased the water-binding ability of tofu. The rheological results suggested that the chia seed mucilage might affect the coagulation process of protein aggregates in soymilk due to the phase separation and electrostatic interaction, resulting in the formation of tofu with distinct rheological property, texture, and water-binding ability.