Influence of pepper and blueberry purees fermented by an autochthonous microbial consortium on the aroma and technological properties of bread

With the aim of obtaining innovative products with peculiar aroma compounds, a controlled fermentation of peppers and blueberries, by an autochthonous microbial consortium of lactic acid bacteria (Leuconostoc mesenteroides and Lactiplantibacillus plantarum) and yeasts (Saccharomyces cerevisiae and Hanseniaspora uvarum), was carried out to produce fermented purees for breadmaking. Breads with unfermented purees and a control were also prepared. An increase in bread specific volume was measured in the puree-enriched samples, overall, in the formulations with the unfermented purees (compared to the fermented ones) and in the blueberry ones (compared to the peppers one). As regards the textural properties, firmness decreased in the puree-enriched samples, with blueberry puree-enriched bread showing the lowest hardness. Doughs enriched with fermented purees were characterized by the higher accumulation of molecules from microbial fermentation including ethanol, isoamyl alcohol, and phenethyl alcohol and esters, such as ethyl acetate and isoamyl acetate, due to the esterase activity of yeasts, especially H. uvarum. The principal component analysis allowed the differentiation of the samples according to the baking process or to the addition of fermented purees; the control samples were located close to the products obtained with unfermented purees. The bioprocessing of vegetables and fruits by fermentation is a suitable way to exploit their potential for developing products with peculiar features.