Defatting strategies for chia protein production: effects on physicochemical properties

The growing demand for sustainable plant-based proteins has highlighted chia seeds (Salvia hispanica L.), offering 18–32 % protein content. This study evaluates protein extraction efficiency and functional properties across two types of chia product: organic partially defatted flour (O) and conventional whole full-fat seeds (C). Defatting methods included mechanical cold pressing (O_PD), hexane extraction (O_HEX, C_HEX), supercritical CO₂ with ethanol (C_SCF), and a non-defatted control (C_ND). Hexane extraction achieved the highest protein content (O_HEX: 67.1 %; C_HEX: 63.9 %) and foaming stability (76.85 %, 75.00 %), with minimal residual fat (0.10–0.40 %). Supercritical CO₂ yielded the highest protein recovery (44.6 %) and emulsion capacity (203.17 %), while O_PD and C_ND showed superior solubility at neutral pH. Functional properties varied significantly: O_HEX exhibited the highest water-holding capacity (794.86 %), and C_HEX demonstrated peak oil-binding capacity (473.92 %). These findings shows that both seed types and defatting method critically influence protein yield and functionality. While hexane extraction maximizes efficiency, its environmental drawbacks position supercritical CO₂ as an eco-friendly alternative, despite solubility trade-offs. This study provides actionable insights for optimizing plant-based protein ingredients by balancing extraction efficiency, functional performance, and sustainability goals across chia seed sources and processing technologies.