Pilot scale production of a non-immunogenic soluble gluten by wheat flour transamidation with applications in food processing for celiac-susceptible people

Celiac disease (CD) is an immune-mediated disease triggered by wheat gluten and related prolamins. A lifelong gluten-free (GF) diet is mandatory to normalize the intestinal mucosa. We previously found that transamidation by microbial transglutaminase of gluten was effective in suppressing the gliadin-specific inflammatory response in CD patients without influencing the main technological properties of wheat flour or semolina. In this study, we produced on a pilot scale a soluble form of transamidated gluten (soluble protein fraction, spf), characterised by a high protein content (88 mg/ml), while native gluten was dramatically reduced (32 +/- 2 ppm; R5-ELISA). Using HLA-DQ8 transgenic mice as a CD model, we found suppression of interferon-gamma secretion in gliadin-specific CD4+ T cells challenged with spf-primed dendritic cells. In terms of functional properties, spf showed both solubility and emulsifying activity values within the range of commercial soluble glutens. Notably, dough prepared by mixing rice flour with spf could leaven. After baking, blended rice bread had a higher specific volume (2.9 +/- 0.1) than control rice bread (2.0 +/- 0.1) and acquired wheat-like sensory features. Taken together, our results highlighted the technological value of transamidated soluble gluten to improve both nutritional and sensory parameters of GF food.