Dynamics of microbial ecology and their bio-preservative compounds formed during the panettones elaboration using sourdough-isolated strains as starter cultures

Abstract

The present study evaluated the application of Limosilactobacillus fermentum IAL 4541 and Wickerhamomyces anomalus IAL 4533 isolated from sourdoughs and their combinations, for bio-conservative action in panettones, as well as to identify the antifungal volatile compounds. Samples from different fermentation steps were submitted to physicochemical and microbiological evaluation, as to know: sourdough after 48 h (A), 96 h (B), and 144 h (C); dough of the first fermentation (D); final dough after second fermentation (E), and baked panettone (F). In all treatments, lactic bacteria and yeast counts demonstrated a mechanism of proto-cooperation. Panettones containing L. fermentum or W. anomalus in their composition had longer shelf life, which indicates their effect as potential biopreservatives. The genetic sequencing data demonstrated the dominance of the Lactobacilli throughout the process, corroborating the data obtained by cultivable methods. A total of 59 volatile organic compounds were found in this study, and a hierarchical cluster analysis presented the separation between the production stages (C, E) and the most recurrent compounds in the final product (F). Of these compounds, the following stood out (n = 26): acids (7.7%), alcohols (23.1%), aldehydes and ketones (34.6%), and esters (34.6%). The treatments containing L. fermentum presented more diversity of volatile organic compounds with potential antifungal effect. There was a higher production of acetic (1.17–8.85 mmol/kg), phenyllactic (5–10.4 mmol/kg), and propionic (3.5–4.3 mmol/kg) acids in the final product. This study demonstrates the feasibility of applying endogenous starter cultures from sourdoughs, with great biopreservative activity, enabling the production of healthier and more natural panettones.