Influence of cell disruption on techno-functional properties and digestibility of Chlorella vulgaris proteins

Abstract

Due to their high protein content, low resource requirements, and high productivity, microalgae are a promising source of potentially sustainable and functional protein. However, the rigid cell wall of Chlorella vulgaris restricts protein bioaccessibility and reduces protein solubility. The latter restricts the techno-functional properties of the protein, presenting challenges for its use in food applications. This study evaluated the impact of cell disruption by high-pressure homogenization (HPH), bead milling (BM), and pulsed electric field (PEF), on protein digestibility and techno-functional properties. To examine the impact of each method, frozen-thawed C. vulgaris biomass was treated with HPH (600 bar and 1200 bar), BM (0.5 and 1 mm beads), and PEF (6 kV/cm, up to 100 kJ/kg). PEF had minimal impact on protein solubility and was excluded from further analysis. HPH and BM significantly improved protein solubility and enhanced in vitro protein digestibility (from 65 % to over 80 %). Emulsion droplet size was reduced, while foaming capacity and stability were enhanced by both HPH and BM. Similarly, these methods reduced the minimal gelling concentration and increased the oil holding capacity. These improvements make disrupted C. vulgaris a competitive alternative to conventional plant proteins. These findings highlight the potential of cell disrupted C. vulgaris as a potentially sustainable, versatile protein source for innovative food formulations.