Bessarabian wild hop sourdough: Microbial characterization and effect on the physicochemical properties and flavor of the bread

The use of wild hops to prepare sourdough starter has been documented in Bulgaria and Bessarabian Moldova since the 19th century. The procedure involves foraging wild hop cones, preparing a decoction, adding corn flour and bran, spontaneously fermenting, and finally drying. To preserve this ancient culinary tradition, currently at risk of falling into disuse, this study characterized the sourdough starter sampled in Bessarabian Moldova and evaluated its effect on the physicochemical properties of bread, compared to commercial yeast. Wild hop sourdough harbored a complex microbial consortium consisting of lactic acid bacteria (Pediococcus pentosaceus, Levilactobacillus brevis and Lactiplantibacillus plantarum) coexisting with yeasts (Saccharomycopsis fibuligera and Saccharomyces cerevisiae). Bread prepared with wild hop sourdough was softer (8.76 N vs 10.52 N), more intensely colored (11.52 vs 7.45 a∗), and richer than control in all flavor compounds related to the proteolytic and amylolytic activities of sourdough, also contributed by the lipid fraction of cornmeal. Hop sourdough protected bread against mold, extending the shelf life by more than 10 days, and increased phenolic compounds (1.21 vs 0.38 mg GAE/g d.m.) and antioxidant activity (1.75 vs 0.39 μmol TE/g by DPPH test, 2.71 vs 1.11 μmol TE/g by ABTS). Flavor improvement and protection against mold suggest broader applications in the baking industry or for other culinary preparations.