Dispersion of zein into pea protein with alkaline agents imparts cohesive and viscoelastic properties for plant-based food analogues

The use of plant-based proteins to replace animal proteins is gaining interest from consumers and food processors, with plant proteins now having become a major ingredient commodity. Even though the commercial plant proteins used today (e.g., soybean and pea) are good texturizing proteins as evidenced by their widespread use in plant-based analogues, they do not show good cohesive and viscoelastic properties. In this study, we describe some natural and food-friendly ways to promote cohesiveness and viscoelasticity using the corn protein, zein, in plant-based protein alternatives. Small deformation tests showed that arginine and/or calcium hydroxide addition to zein-pea protein blends significantly increased elasticity and cohesiveness. Arginine did not perform as well as calcium hydroxide to provide strength to pea protein, though its effect on improving elasticity was good. A lubricated squeezing flow test showed that all blends had strain rate thickening/hardening behavior and blends were highly resistant even at higher deformation rates. Textural attributes of the blends were able to be modified with combination treatments to achieve different textural product specifications. Secondary structure composition analysis by FT-IR emphasized the importance of β-sheet content in enhancing the material viscoelastic properties. Arginine and calcium hydroxide-incorporated blends presented the highest β-sheet content. Imaging on blends using scanning electron and confocal microscopy showed that zein formed viscoelastic fibrils holding the structure together through a dispersed network. In conclusion, zein with an added alkaline agent provides cohesiveness and viscoelasticity to plant-based formulations for potential replacement of currently used chemically-modified hydrocolloids or wheat gluten in formulations for meat substitutes, such as analogues of chicken tenders, burger patties, and hotdogs.