Identificação e seleção de cepas de fermentos naturais de diferentes regiões da Paraíba e estudo do potencial tecnológico e bioativo para panificação

Abstract

This study aimed to develop a dominant sourdough starter with controlled characteristics, derived from strains of Lactic Acid Bacteria (LAB) isolated from different climatic regions of Paraíba, with technological and bioactive potential. Initially, four sourdough starters were collected from municipalities within the humid, subhumid, and semi-arid regions. The microbiota of these starters was isolated and preliminarily identified. Out of 129 isolates obtained, 24 exhibited typical LAB characteristics and were identified by mass spectrometry (MALDI-TOF) as Lactiplantibacillus plantarum, Companilactobacillus paralimentarius, and Levilactobacillus brevis. C. paralimentarius predominated in the humid region, while L. plantarum dominated in the other regions. Through principal component analysis (PCA), 17 strains were selected for their superior technological potential. These strains were tested for stress tolerance to acid, salt, sucrose, and ethanol at various concentrations. L. plantarum 47 (Lp47) and L. brevis 83 (Lb83) were selected by PCA due to their superior performance for use as starter cultures. Lp47 was the most tolerant under acidic and saline conditions, while Lb83 stood out for its higher survival at high ethanol concentrations. These strains were selected for the development of the sourdough starter and demonstrated good physicochemical, bioactive, and technological performance. The rapid growth and acidification of Lp47 and Lb83 are directly associated with their autochthonous origin and adaptation to the stressful conditions of the sourdough. However, Lp47 acidified the medium more quickly, stabilizing its viable cell count after 4 hours of fermentation, while Lb83 stabilized its count after 6 hours. Both starters exhibited antioxidant activity and an increase in phenolic compounds during fermentation, with no significant difference between them (p>0.05). In terms of rheology, the rigidity of the samples after 8 hours of fermentation was approximately 10 times greater than that of the samples fermented for 24 hours. The results demonstrated the feasibility of using Lp47 or Lb83 as starter cultures for sourdough, highlighting that autochthonous strains excel in technological development in baking processes and are recommended for initiating this process in a rapid, controlled, and safe manner.