Development of high-protein pea-based gels for cheese alternatives: Modulating gel properties via enzymatic...

Consumer demand for plant-based cheese alternatives continues to rise yet developing high-protein gels that provide the structural and functional properties required for cheese preparation remains challenging. This study aimed to produce high-protein pea protein isolate (PPI) gels by enzymatically modifying the proteins through partial hydrolysis, partial deamidation, and transglutaminase (TG)-induced crosslinking during fermentation, followed by pressing. Using these approaches, gels containing up to 17% protein and 20% fat were successfully produced across all formulations. Pressing reduced moisture from 76% to 62-65%, leaving approximately 10% free water in the final gels, irrespective of enzyme treatments, whereas TG treatment increased the proportion of bound water, indicating enhanced water immobilisation within the protein network. Despite similar overall composition, enzymatic modification markedly influenced gel hardness, enabling textures ranging from soft to semi-hard. TG addition increased hardness from 257 g to 767 g in unmodified PPI, comparable to reference Danbo cheese (804 g). Deamidation had limited effect on hardness, whereas partial hydrolysis produced softer gels (406 g with TG; 138 g without TG). Deamidation increased elasticity (G' from 28,000-50,000 Pa to 33,000-61,000 Pa with TG), reaching values similar to Danbo cheese. Visual assessment showed that TG-treated unmodified PPI formed rough, porous structures, while deamidated PPI produced smoother, more uniform surfaces, demonstrating improved network organisation. Overall, the results show that combining deamidation or partial hydrolysis with TG-mediated crosslinking effectively modulates gel hardness and elasticity without compromising nutritional composition, yielding high-protein pea protein-based gels with promising physicochemical characteristics for the potential development of plant-based cheese alternatives.