Mixing plant-based proteins: Gel properties of hemp, pea, lentil proteins and their binary mixtures

One of the challenges in substituting dairy products by alternative proteins is that the properties of mixed protein gels cannot necessarily be predicted by those of single protein gels, whereas the need of mixing is often driven by nutritional aspects. However, mixing plant proteins could also open a door to new textures. The main goal of this study was to investigate the impact of binary mixing of hemp (H), yellow pea (P), and brown lentil (L) protein concentrates/isolates on their gel and water-holding properties. Dispersions of reconstituted proteins and mixtures thereof were gelled using glucono-δ-lactone (GDL), transglutaminase (TG), and temperature (T) at a protein content of 12% (w/w). Mixtures of pea and lentil proteins showed gel strengths for TG- and T-induced gels that are proportional to the ratio of the mixture constituents (linear mixing behavior), whereas synergistic effects were observed for GDL-induced gelation. In contrast, all mixtures containing hemp exhibited a non-linear mixing behavior for the three gelation methods, usually resulting in lower gel strengths compared to theoretically expected values. The study showed that mixing plant-based proteins of different protein sources can lead to very different mixing behaviors in terms of gel properties, showing either a reinforcing, an indifferent or a weakening effect compared to the theoretically expected properties. The results can help developing more targeted plant protein-based soft gel products such as yogurt alternatives with specific techno-functional properties, while adjusting the nutritional characteristics.