Microbial stabilization and protein functionality of plant-based liquids using pulsed electric fields

Plant-based meat substitutes are popular due to their lower environmental impact and their role in healthy diets, compared to animal products. They are typically produced by extrusion, where protein isolate powders are hydrated and structured into meat-like textures. However, conventional protein extraction and drying processes are high-temperature and energy-intensive and impair protein functionality, which is crucial for texturization. This thesis proposes a more sustainable approach based on minimal processing and the elimination of drying. Two liquid ingredients were investigated: Chlorella suspension and pea protein extract (PPE), obtained under mild aqueous conditions.

Given the microbiological instability of liquids, pulsed electric field (PEF) treatment was evaluated as a mild preservation strategy. PEF achieved significant microbial inactivation and extended shelf life for both ingredients. Moreover, unlike conventional heat pasteurization, PEF enhanced the functionality (gelling properties) of pea proteins. Texture formation during extrusion was maintained when incorporating Chlorella suspension or PEF-treated PPE into pea protein isolate. Overall, PEF improved sustainability and functionality of plant-based foods.