Modulation of pea protein isolate hydrogels by adding kappa-carrageenan: gelling properties and formation mechanism

Our study focuses on the gelling properties of pea protein (PP), which are comparatively weaker than those of other plant proteins, thereby limiting its application. However, we found that the addition of κ-carrageenan (κ-CAR) significantly (P < 0.05) increased PP gels' hardness and water-holding capacity irrespective of gel formation temperature (80 or 95 °C). Rheological and microstructural analysis confirmed a synergistic effect between PP and κ-CAR, with higher synergy values observed in hydrogels formulated at 95 °C. Molecular force studies revealed that non-covalent interactions were dominant, with disulphide bonds contributing only to the structure of gels formed at 95 °C. These promising findings not only enhance our understanding of the PP and κ-CAR gel formation mechanism but also hold practical implications, potentially leading to improved gelling properties of PP and expanding its applications in the food industry.