Gelling capacity of cell-disrupted Chlorella vulgaris and its texture effect in extruded meat substitutes

Abstract

Microalgae attract increasing interest in enhancing the nutritional values of plant-based foods. However, alterations in the final product’s color (by green algae) and mushy texture can be induced. In this study, we incorporated yellow Chlorella vulgaris (Cv) in pea protein-based meat substitutes and aimed to minimize properties alteration by using wet and disrupted Cv biomass. The cell wall disruption, done by high-pressure homogenization (HPH) at 150 MPa and initial biomass temperature below 10 °C, significantly increased the gelation capacity. The effect was confirmed by (i) a 10x increase in the apparent viscosity of 14% (w/w) Cv suspensions, and (ii) a 2x increase in the storage modulus (G’) of 9:1 (w/w) pea protein isolate - Cv gels. Furthermore, the HPH-treated Cv was successfully incorporated (10% (w/w)) into pea protein-based meat substitutes produced with high-moisture extrusion cooking without altering their visual appearance, hardness, or anisotropy index. Finally, spray drying or fractionation steps of the HPH-treated Cv did not improve protein gels, or meat substitutes produced thereof. This study demonstrated that disrupted Cv is a promising nutritious and sustainable ingredient for meat substitutes.