This study investigated calcium sulfate and chitosan on the textural modification and microstructure of tofu made from lentils. The addition of varying amounts of calcium sulfate (0–12 mM) and chitosan (0–1.0%) into lentil milk could affect the gel properties of lentil-based tofu. The gel properties, including the hardness and cohesiveness, of lentil-based tofu significantly increased with the addition of 12 mM calcium sulfate, exhibiting a slightly discontinuous network structure and a slightly regular pore network. However, the gel properties including hardness and cohesiveness significantly decreased with the addition of 1.0% chitosan, presenting a slightly continuous network structure with pores. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed that the aggregation of the vicilin, legumin acidic unit and legumin basic unit proteins in lentil milk was induced both by 12 mM calcium sulfate and 1.0% chitosan. Our results suggested that calcium sulfate and chitosan could affect the gel properties, such as hardness and cohesiveness, of lentil-based tofu. Therefore, calcium sulfate and chitosan can be used as practical food additives for the development of texture-modified lentil-based tofu.

This study investigated the effects of the addition of chitosan (0–1.0%) or glucono-δ-lactone (GDL) (0–60 mM) on the gel properties, microstructure, and texture of pea-based tofu-type product. Following the addition of 0.5% chitosan or 20 mM GDL, we observed a significant decrease in the hardness and cohesiveness of the tofu, resulting in a slightly discontinuous network structure with pores smaller than those in samples without chitosan or GDL. SDS-PAGE analysis revealed the induced aggregation of pea legumin (11S) and vicilin (7S) subunits (30, 34, and 50 kDa), legumin α subunit (40 kDa), and legumin β subunit (20 kDa) by chitosan or GDL. It appears that chitosan and GDL could potentially be used as food additives for the development of texture-modified pea-based tofu-type products.