Effects of Low-Allergen Wheat and Bayberry Leaf on Wheat Bread: A Comparison with Commercial Wheat

Gliadin and glutenin wheat proteins are major food allergens. The allergenicity of various wheat products, such as bread, can be reduced by substituting flour with plant-derived tannins. Here, we investigated a technique for reducing the allergenicity of wheat by utilizing the properties of proanthocyanidins (PAs), which strongly bind to proteins. We compared commercial bread wheat (BW), low-allergen wheat (1BS-18 "Minamino Kaori"; 1BS-18M), and bayberry leaves (BBLs). Allergenicity was investigated through enzyme-linked immunosorbent assays (ELISAs) and Western blotting (WB). The immunoreactivity of wheat allergens in both BW and 1BS-18M decreased in a concentration-dependent manner with BBL substitution, and the effect was greatest at 10%. The antioxidative properties also increased with BBL substitution, and the highest antioxidative property was observed at 10%. The specific volumes of both BW and 1BS-18M decreased while the a* value (green to red) increased with increasing BBL substitution. In contrast, no significant differences were observed in the texture of breads with 0% (control), 3%, or 5% BBL substitution. However, 10% BBL substitution led to a significant (p < 0.05) reduction in the texture of the bread. Therefore, 5% BBL substitution is optimal for achieving low allergenicity and improved antioxidative properties while maintaining quality.