Glucono-δ-lactone-induced gels from lentil protein fractions: insights into rheological, textural, and water-holding properties.

BACKGROUND

The gelation behavior of individual lentil protein fractions and subfractions remains insufficiently understood despite their potential for plant-based structured food applications. Therefore, this study investigated the glucono-δ-lactone (GDL)-induced gelation and gel properties of lentil protein isolate (LPI), its protein fractions, including albumin (ALB), globulin (GLO), and glutelin (GLU), and the globulin subfractions legumin (LEG) and vicilin (VIC).

RESULTS

Pronounced fractionation-dependent differences were observed in gelation kinetics, rheological properties, gel strength, water-holding capacity (WHC), and microstructure. VIC exhibited the fastest network development and the highest storage modulus. Gel strength followed the order VIC > ALB > LP > GLU > GLO > LEG, with the highest value observed for VIC (412.10 g). Similarly, WHC was highest in VIC gels (93.48%), whereas LEG exhibited the lowest value (77.15%). Intermolecular interaction analysis showed that hydrophobic interactions and disulfide bonds were the dominant stabilizing forces. Fourier transform infrared results indicated notable structural rearrangements during acidification, particularly in VIC- and ALB-rich systems. Scanning electron microscopy observations confirmed a compact and uniform network for VIC gels, whereas LEG gels exhibited a coarse and discontinuous structure.

CONCLUSION

Protein fractionation significantly influences gelation behavior and network structure. VIC-rich fractions demonstrate superior gel-forming ability and show strong potential for the development of plant-based structured food systems. © 2026 Society of Chemical Industry.