Non-Thermal Matrix Engineering of Functional Foods: A Review of Mechanisms, Bioaccessibility, Safety, and Regulatory Readiness

Non-thermal processing technologies: high-pressure processing (HPP), pulsed electric fields (PEF), ultrasound (US), and cold plasma (CP), are increasingly investigated as tools for food matrix modification and preservation. This structured critical narrative review evaluates cell wall disruption, protein conformational change, polysaccharide modification, nutrient retention and release, microbial safety, scale-up, and regulatory readiness. Claims are classified according to the measured endpoint: analytical retention or extractability; static or dynamic in vitro bioaccessibility; epithelial uptake; fermentation; systemic bioavailability; or human bioactivity. The evidence does not support universal superiority over thermal processing. Outcomes depend on matrix composition, target compound, process intensity, temperature history, storage, and analytical method. Thermal treatment can outperform non-thermal alternatives for carotenoid release, antinutritional factor reduction, enzyme control, and spore inactivation. HPP is commercially mature but remains capital intensive and can leave residual enzyme activity. PEF is effective in continuous, pumpable products but is constrained by conductivity and electrode conditions. Ultrasound exhibits non-linear release-versus-oxidation behavior and scale-dependent cavitation; and CP requires compound-specific chemical and toxicological validation. Matrix engineering is therefore defined here as the deliberate, measurable alteration of food structure to obtain a specified endpoint without assuming systemic bioavailability or health benefit. Product-specific validation remains essential.