Allergenic risk assessment of porcine myoglobin expressed by engineered Komagataella Phaffii

Myoglobin produced by fermentation using engineered Komagataella phaffii is an important color additive in meat analogue products, but its allergenicity is poorly understood. Here, we initially searched the Allergen Online database and did not find any allergic or cross-reactive proteins in porcine myoglobin (PM). In vitro simulated digestion demonstrated that PM did not exhibit notable acid-base resistance or anti-digestion capabilities. However, sensitization was observed in BALB/c mice, including a significant increase in specific antibodies and biomarkers for allergic reactions, as well as alterations in gut microbiome and serum metabolome. Interestingly, the intensity of sensitization exhibited a negative correlation with the purity of PM. 60 and 88% purities showed weaker sensitization compared to the ovalbumin control group. These allergic reactions were likely due to the non-myoglobin protein portion, highlighting the importance of purification processes and the urgent need to assess the allergenicity of this portion.