Sourdough and Gluten-Free Products

Celiac disease is one of the most common food intolerances, with an incidence of 1 in every 100 people worldwide, a number that is expected to rise [1]. Meta-analysis of the incidence of celiac disease worldwide over the past number of decades has reported a 7.5% increase in the prevalence of gluten sensitivity among both men and women, with a higher detection rate identified in women [2]. Lifelong avoidance of gluten-containing cereals and related products is the only effective treatment for people who suffer from celiac disease. Foods that are not allowed in the gluten-free (GF) diet are all the gluten-containing products prepared from barley, Kamut, oat, wheat and their derivates, in which the gluten content exceeds 20 mg/kg on a total basis [3]. As consumer demand for GF products is rising, food technologists and manufacturers are called upon to satisfy the increasing demand [4]. In particular, people who suffer from celiac disease and those who are allergic to gluten ask for high-quality GF products, with the same textural, sensorial, and nutritional properties as their gluten-containing counterparts [5, 6]. Nonetheless, the replacement of gluten with gluten-free ingredients in conventional products, primarily bread and pasta, constitutes a major technological challenge for the food industry. Gluten represents the structure-forming protein in the flour, and it is responsible for the unique viscoelastic properties (extensibility, resistance to deformation, mixing tolerance, and gas-holding capacity) of the dough [7]. The proteins present in GF flours do not possess these fundamental structural features, and, upon mixing, a weak batter, resembling a cake dough, is obtained [8]. Because of the impaired rheological properties of the GF batters in comparison to conventional doughs, most of the GF products available on the market are characterized by overall low quality, lacking flavor and showing poor textural characteristics and mouthfeel [5, 9]. Furthermore, as GF products are mainly made from starch and are generally not fortified [10], their contribution in terms of different nutrients, such as folate, B vitamins, minerals including iron and dietary fiber, is poor [11, 12].