Gelation behavior of lentil protein aggregates induced by sequential combination of glucono-δ-lactone and transglutaminase

This study introduces a cold-set lentil protein (LP) gel with significantly improved mechanical strength prepared from protein fibrillar aggregates. First, fibrillar aggregates were formed by thermal treatment at an alkaline pH. Subsequently, glucono-δ-lactone (GDL), transglutaminase (TG), or their sequential combination (GDL/TG) was applied to induce the gelation of LP aggregates at room temperature. The gelling mechanism study revealed the formation of covalent bonds in the gel network induced by TG, which was then reinforced by hydrophobic interactions among the protein aggregates induced by GDL. As expected, the sequentially addition of TG and GDL enabled formation of interconnected networks with thick walls and significantly improved gel hardness. This research has provided a new strategy to develop strong lentil protein gels for food texturization thus potentially expanding food applications of lentil protein as an advantageous plant source of protein.