Utilization of both soluble and insoluble pulse fractions in the development of thermally processed mixed-colloidal dispersion gel

The tendency towards healthier and sustainable diets has increased demand for natural plant-based emulsifiers and reduced-fat gels. Combining pulse protein-based emulsion and starch-rich insoluble fraction of pulses could lead to a desirable texture of sauces and spreads. Faba bean flour dispersion was centrifuged to separate the soluble proteins from the insoluble proteins and starch-rich fractions. The mixed colloidal dispersion was then prepared by mixing soluble protein-stabilized O/W emulsions (0-15 wt.% oil content) with the insoluble fraction (0-15 wt.% solid content), followed by inducing starch gelatinization through heating at 90°C. The results showed that the gelatinized starch dominates the particle size of the mixed dispersion due to its larger size than the oil droplets. Visually, the prepared gels showed a decrease in flowability and surface gloss with an increase in both oil and insoluble fractions. The L*, representing the lightness, decreased with an increase in the insoluble fraction. The gel strength was more significantly impacted by the insoluble fraction than the oil content due to the formation of packed swollen starch granules network. Storage moduli increased about 10000 times when the solid content of insoluble fraction increased from 0 to 15 wt.% at a constant oil content. However, a similar increase in oil content led to only about 7 times increase in storage moduli at a constant solid content. For syneresis, not only does the insoluble fraction play an important role, but also higher oil content helps lower water release from the gel network. The separation of soluble and insoluble pulse fractions and the application of the soluble one for emulsion preparation before any thermal gelation is necessary as the small oil droplets help prevent coalescence and oiling-off. This study provides valuable insight into designing a desirable texture of mixed-colloidal dispersion gels by a complete utilization of pulse flour.