Transglutaminase mediated crosslinking of pea protein: from rheology to proteomics

Abstract:Despite the widespread application of transglutaminase (TG) as a processing strategy to enhance structure in protein-based systems, detailed insights spanning macro-to molecular-level mechanisms remain limited. This study investigates TG-mediated crosslinking of pea protein by integrating rheological, chemical, and proteomic analyses to establish a comprehensive structure–function relationship. Dispersions of 10 % w/v pea protein were treated using TG (from Streptomyces mobaraensis) dosages of 0–10 U/g protein at 40 °C, pH 7. Rheological measurements (time sweep of 5 h, 40 °C) showed a significant increase in storage modulus (G′) during incubation with TG and altered gelation dynamics (measured by frequency sweep from 0.062 to 62 rad/s and a strain sweep from 0.0001 to 10). A clear dose-dependent relationship, indicating enhanced network formation was noted. The concentration of free ε-amino groups, quantified using the o-phthalaldehyde (OPA) method, decreased with higher TG levels, confirming progressive covalent crosslinking while SDS-PAGE further revealed differential participation of pea protein fractions in the crosslinking reaction. Proteomic profiling via LC-MS/MS (5 % false discovery rate, Pisum sativum FASTA) indicated that TG preferentially crosslinks glutamine and lysine residues near glutamic acid or in disordered regions, with specific adducts enriched in these areas. These peptide-level modifications correlate with macroscopic insights from the study, providing a molecular framework for designing protein-based systems with tunable mechanical properties for plant-based and conventional foods.

Publication year:2026

Keywords:Food & animal science & technology, Applied chemistry & chemical engineering

Accessibility:Embargoed

Review status:Peer-reviewed