How organic farming of wheat may affect the sourdough and the nutritional and technological features of leavened baked goods

Organic farming is gaining broad recognition as a system that complies well with sustainability, an overarching principle that should drive agriculture now and in the coming year. Different cultivars and products can harbour different abundances of specific bacterial groups, farming system may influence the composition and abundances of microbial communities found on food product. Despite the growing interest towards organic foods, we still have a limited understanding of the diversity of food-associated microbial communities and the factors that influence the composition of these communities. Consumers in developed nations are commonly exposed to differences in farming practices through their choice between organic and conventionally farmed foods. Organic farming practices can differ from conventional farming practices in a variety of ways, including the types of fertilizer and pesticides that are used. This review aiming to gather current knowledge on chemical, technological, toxicological and functional properties and microbiota composition of wheat flours originating from organic and conventional farming systems and how the use of these may affect the sourdough fermentation and breadmaking. Sourdough fermentation is the most natural and best-performing process to ensure optimal sensory and functional characteristics. It fits perfectly into the processing chain that starts with the organic farming, especially for old wheat varieties with weaker technological properties. Recently, organic and sourdough microbiota diversity was investigated and in some case a comparison between organic and conventional microbial ecosystem was also carried out. Opposites evidences arise. Once a higher diversity of lactic acid bacteria species was found in conventional wheat sourdoughs, while when the diversity of Firmicutes was investigated, organic sourdoughs showed the highest complexity. When occurring, the differences between conventional and organic sourdough microbiota and their effects on bread properties are difficult to be identified and categorized due to the extremely large variability in baker's practices. Besides, this review would provide a critical view of this topic in order to avoid the speculation that in this field unavoidably arise.