Effects of different processing on allergenicity of wheat gliadin in non-fermented dough

Abstract: Food allergy has become a major public health and food safety issue concerned by the world . In the world, 0.2% -0.9% of adults and 0.4%-1.3% of children suffer from wheat allergy, which seriously affects the lives of allergic patients. The structure of food allergens can be changed by processing, which maight affect their allergenicities. Therefore, it is meaningful to study the influence of different processing on the allergenicity of gliadin in non-fermented dough. Here non-fermented dough were treated by different processing such as thermal processing (boiled, baked, microwave, high temperature and high pressure), cold treatments (liquid nitrogen, quick freezing machine) and non-thermal processing (static ultrahigh pressure, irradiation, pulsed light, ozone and ultrasonic). The molecular weight and the allergenity of wheat gliadin in non-fermented dough after various processing were determined by SDS-PAGE and the double antibody sandwich ELISA. SDS-PAGE electrophoresis results showed that the molecular weight of wheat gliadin in non-fermented dough changed significantly after boiled, baked or high temperature and high pressure treatment. The results of Sandwich ELISA showed that when the holding pressure temperature was 35℃ and the holding time was 20 min, the non-fermented dough wheat gliadin was treated with 100 -300 MPa ultra-high static pressure, its allergenicity increased first, then decreased, and then increased again, of which its allergenicity significantly decreased to 80.94% when treated at 250 MPa, and significantly increased to 127.27% or 128.17% when treated at 200 or 300 MPa, respectively, indicating that ultra-high static pressure treatment has a allergenicity increasing effect of gliadin in non-fermented dough; Irradiation treatment with γ-60Co at a dose of 1-15 kGy resulted in the allergenicity of gliadin in non-fermented dough decreased first, then increased and then decreased again, at 7, 13 kGy, the allergenicity decreased to 72.32% or 84.03%, respectively; The allergenicity of non-fermented dough wheat gliadin was significantly reduced after these hot, cold and non-heat processing treatments (P<0.05). After 2 hours of 500-watt ultrasonic treatment, its allergenicity was reduced to 90.23%; after Microwave, Quick-freezer, Pulsed light, or Baked treatment, it was reduced to 85.36%, 79.49%, 79.08% or 76.69%, respectively. Among them, the most significant (P<0.01) reduction in allergy was observed after Boiled, High temperature and high pressure, Liquid nitrogen, Ozone and Pulsed light (PL-1) treatment, and all of which decreased to about 60%, and ranked following by Boiled> Ozone fumigation 30 min (O3-1)> Liquid nitrogen> Pulsed glare 1 (PL-1)> High temperature and high pressure> Ozone fumigation for 60 min (O3-2). In short, the processing modes can significantly affect the allergenicity of non-fermented dough wheat gliadin, which can be used as an effective method for the safety control of food allergens and provide an effective reference for the production of desensitized food. At the same time, people's daily diet can be healthier by choosing a suitable processing method, especially for wheat susceptible people. Of course, the influence of different processing methods on the decreasing allergenicity of non-fermented dough wheat gliadin need to be further validated in combination with other in vivo experiments and especially the clinical trials of wheat susceptible people.