Allergenicity Assessment of Precision Fermentation-Derived Food Proteins

Precision fermentation (PF) yields single, well-characterized recombinant proteins, such as dairy and egg white proteins, at an industrial scale, and several products have reached the market. Numerous PF-derived proteins, including ovomucoid and β-lactoglobulin, are known allergens designed as exact structural copies of their native homologs; hence, assessments center on equivalence rather than novel hazards. Therefore, the current tiered scheme of allergen database comparison, digestibility testing, and serum immunoglobulin E binding assays is applicable. Nevertheless, residual host cell proteins, altered host-dependent enzymatic glycosylation, and process-related impurities render PF-derived products imperfect replicas, and thermal and high-pressure processing, enzymatic hydrolysis, and non-enzymatic glycation can modify linear or conformational epitopes, thereby reducing IgE binding or generating neoepitopes. Because these effects depend on structural attributes acquired during production, including folding stability, disulfide bonding, glycosylation, and proteolytic resistance, PF-derived proteins and native proteins may respond differently to identical processing. This review explores the molecular attributes acquired at each stage of PF production and the epitope changes originating during processing, reevaluates the current assessment scheme, and outlines considerations for a premarket safety framework reflecting realistic processing and consumption conditions.