Biotechnological treatment for bakery to increase dough structure, shelf–life and sensory properties.

Gluten is the major factor involved in the structural properties of bakery products. Thanks to its ability to create aggregates, it gives dough viscosity, elasticity and cohesion, all features responsible for the baking performance. Gluten is composed of extensible, viscous gliadins and rigid, elastic glutenins. Moreover, the gliadin protein fraction is the main factor responsible for the development of celiac disease (CD) and other non-celiac gluten sensitivities. Nowadays, the development of new technologies in the food industry aims to both improve products already marketed, and to develop new gluten-free products. The purpose of our work was to set up a biotechnological process based on the combined use of cross-linking enzymes and selected microbial consortia to produce new gluten free bakery products with improved shelf-life, and sensory properties. Cross-linking enzymes, able to organize and create protein networks, are suitable for the food industry as protein modifiers. Among those enzymes, Transglutaminase (TGase) is surely a potentially interesting tool for its capacity to enhance the cohesiveness and elasticity of the dough, solving the problem of lack of consistency of gluten-free flours. Our research showed that the microbial TGase (from Streptoverticillium mobaraense) has the capacity to modify wheat flour proteins and determine protein network formation responsible for a major molecular structural stability of the product. The TGase effect on flour mainly involved gluten and globulin fraction modification. The results showed that the enzyme activity in the presence of a selected microbial consortium of lactic acid bacteria and yeasts (Lactobacillus sanfrancisciencis and Candida milleri) caused synergic effects on the sensory, rheological and shelf-life features of the products. These features resulted significantly affected also by formulation and process variables. Based on our results, we are evaluating the gluten-free flours of corn, rice, amaranth and lentil, to develop a new bakery product for people with gluten sensitivities.