Enhanced functionality and reduced allergenicity of silkworm pupae protein through Lactiplantibacillus plantarum fermentation.

With rising demand for sustainable protein sources, insect proteins have gained attention for their nutritional value and environmental advantages. Silkworm pupae protein (SPP) is rich in essential amino acids and bioactives but has limited application due to poor solubility and high allergenicity. This study employed Lactiplantibacillus plantarum A2 (A2) to ferment SPP and evaluated structural, functional, and allergenic changes in vitro and in mice. Fermentation increased α-helix content, surface hydrophobicity, and sulfhydryl groups while reducing β-sheet content and fluorescence. Hydrolysis degree, emulsifying stability, foaming, and antioxidant activity (DPPH, ABTS, FRAP) were significantly enhanced. IgE-binding decreased by 22% and hyaluronidase inhibition rose by 80%, suggesting reduced allergenicity. Fermented protein alleviated allergic symptoms in mice, and small intestinal hydrolysates showed the highest antioxidant activity and lowest allergenicity. These findings indicated that A2 fermentation effectively improves SPP's structural and functional properties, supporting the potential benefit in functional and hypoallergenic food applications.