Food Res Int. 2026 Dec 1;245(Pt 4):120885. doi: 10.1016/j.foodres.2026.120885. Epub 2026 Sep 25.
ABSTRACT
Global population growth and climate change intensify demand for sustainable protein sources. Defatted hemp seed (DHS), a protein-rich by-product of hemp oil extraction, remains underutilized in food applications. In this study, hemp seed tofu-like gels (HSTG) were produced from DHS through heat-induced coagulation using five food-grade coagulants: MgCl₂, CaCl₂, CaSO₄, glucono-δ-lactone (GDL), and transglutaminase (TGase). The composition-structure-function relationships of the resulting gels were systematically investigated. Physicochemical, structural, and nutritional properties were analyzed, including yield, texture, moisture content, microstructure by SEM, protein secondary structure by FTIR, protein profiles by SDS-PAGE, free sulfhydryl/disulfide contents, in vitro protein digestibility, and amino acid composition. Gelation behavior was governed by coagulant-dependent molecular interactions, particularly disulfide bonding and hydrophobic interactions that influenced protein network formation. Among the coagulants, MgCl₂ and TGase produced the firmest gel networks, whereas GDL resulted in softer gel structures. CaCl₂ treatment yielded the highest in vitro digestibility (88.11%), and the IVPD values of all HSTGs were 1.9-2.6 times that of DHS. Amino acid analysis revealed increased total amino acid contents (g/100 g protein) and improved nutritional indices, including essential amino acids and branched-chain amino acids, depending on the coagulant type. These findings link molecular interactions and protein secondary structure to macroscopic gel properties and demonstrate that DHS can be effectively upcycled into functional tofu-type protein gels, highlighting its potential as a sustainable strategy for plant-based food development.
PMID:42967711 | DOI:10.1016/j.foodres.2026.120885