A review of wheat allergy: allergens characteristic, the impact of processing on allergenicity and future perspective

Background

Wheat is the most widely cultivated crop worldwide but it triggers allergies in 0.2–1.0 % of the global population. Clarifying characteristics of wheat allergens and reducing their allergenicity is the basis for preventing and solving wheat allergy.

Scope and approach

This review concluded the characteristics, structures and epitopes of wheat allergens, especially major allergens (Tri a 14, Tri a 15, Tri a 17, Tri a 19-Tri a 21, Tri a 26, Tri a 28-Tri a 30, Tri a 36, Tri a 37 Tri a 40). Impacts of various processing techniques on wheat allergenicity was also assessed and compared, including heating, acid treatment, enzymatic hydrolysis, fermentation, polyphenol modification, high-pressure treatment, ultrasound, irradiation and genetic modification, etc.

Key findings and conclusions

Wheat allergenicity was closely related to characteristics, structures and epitopes of wheat allergen. Among the various techniques, heating, enzymatic hydrolysis, fermentation are effective in decreasing the wheat allergenicity due to the disruption of epitopes and the decrease of allergens mainly induced by protein degradation. Additionally, fermentation and polyphenol modification decrease human sensitivity to allergens. It is difficult for irradiation at safe dosages (≤10 kGy) to decrease wheat allergenicity. Other processes (e.g., acid treatment, high-pressure treatment, ultrasound) may work under certain condition. Considering many factors such as the effect of reducing allergenicity, cost, and nutritional value, fermentation and its combined multiple techniques may be the best method to reduce wheat allergenicity. Of note, before producing hypo-allergenicity wheat-based foods, large-scale clinical trials must be conducted to determine their low allergenicity.