TARGETED FERMENTATION APPROACHES FOR SUSTAINABLE PRODUCTION OF CELIAC-SAFE BREAD VIA BIOCHEMICAL CHARACTERIZATION OF SOURDOUGH MICROBIOMES

Bread is a staple food product worldwide, but current bread manufacturing practices fall short in addressing consumer demands for "clean label" products that satisfy dietary requirements like "gluten-free". This has led to bread being the greatest contributor to food waste. Increasing global population and increasing prevalence of gluten intolerances such as celiac disease demand a sustainable solution for producing staple food items that satisfy consumers in terms of quality and safety. The objective of this proposal is to evaluate the potential for the ancient technology of sourdough fermentation to be harnessed and used for targeted development of high-quality, celiac-safe bread products. We propose an integrated approach with our combined expertise in food microbiology and nutritional biochemistry using next generation sequencing methods and an in vitro model of the intestinal barrier to characterize the relationship between microbiome structure, bread structure and gluten immunogenicity.We hypothesize that select sourdough microbiomes impact the hydrolysis of gluten, driving differences in functional outcomes of bread products including bread texture, shelf life and gluten immunogenicity within the context of celiac disease. We will test this hypothesis using the following specific aims:Aim 1: Characterize sourdough starter culture microbiomes relative to time, gluten hydrolysis, and bread stability.Hypotheses: 1a. Sourdough microbiomes (diversity and abundance) are stable over time (passages and storage) 1b. Metagenome functional content of sourdough microbiomes will contain microorganisms and microbial activity for gluten hydrolysis. 1c. Sourdough microbiomes can impact bread stability and shelf life.Aim 2: Investigate the potential protective effects of unique sourdough microbiomes against gluten-mediated inflammation in vitro.Hypotheses: 2a: Fermentation by unique sourdough microbiomes reduces the inflammatory capacity of gluten in in vitro models of CD. 2b: Gluten degradation is influenced by the unique microbial profile of each sourdough starter. 2c: Gluten-mediated inflammation in vitro is dependent on sourdough microbiome storage and passage time.Successful completion of these aims will elucidate microbial consortia which contribute to bread stability and demonstrate the potential for sourdough fermentation to produce celiac-safe bread, providing and critical data for the development or targeted processing approaches for bread production. By improving the knowledge and understanding of fermented food microbiomes as ingredients, we will be able to use these microbiomes as processing tools to sustainably improve safety, quality and shelf life of bread and other fermented foods.