title: Microbiological profile of maize and rye flours, and sourdough used for the manufacture of traditional Portuguese bread.
abstract: A thorough microbiological study of maize and rye flours, and sourdoughs obtained therefrom for eventual manufacture of broa--a dark sour bread typical in Northern Portugal, following artisanal practices, was carried out. Towards this purpose, samples were supplied by 14 artisanal producers, selected from 4 sub-regions, during two periods of the year. Total viable counts, as well as viable mesophilic and thermophilic microorganisms, yeasts and molds, Gram⁻ rods, endospore-forming and nonsporing Gram⁺ rods, and catalase⁺ and catalase⁻ Gram⁺ cocci were assayed for. The comprehensive experimental dataset unfolded a unique and rather complex wild microflora in flours and sourdoughs throughout the whole region, which did not discriminate among sub-regions or seasons, or flour source for that matter. However, fermentation played a major role upon the numbers of the various microbial groups: the viable counts of yeasts, lactobacilli, streptococci, lactococci, enterococci and leuconostocs increased, whereas those of molds, Enterobacteriaceae, Pseudomonadaceae, staphylococci and micrococci decreased.
authors.affiliation: CBQF/Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Dr. António Bernardino de Almeida, P-4200-072 Porto, Portugal.
authors.forename: João M
authors.initials: JM
authors.lastname: Rocha
authors.forename: F Xavier
authors.initials: FX
authors.lastname: Malcata
mesh_terms: D001939:Bread / Q000382:microbiology*; D015169:Colony Count, Microbial; D005285:Fermentation; D005433:Flour / Q000382:microbiology*; D005511:Food Handling / Q000379:methods; D006090:Gram-Negative Bacteria / Q000254:growth & development / Q000302:isolation & purification; D006094:Gram-Positive Bacteria / Q000254:growth & development / Q000302:isolation & purification; D007778:Lactobacillus / Q000254:growth & development / Q000302:isolation & purification; D011174:Portugal; D012434:Secale / Q000737:chemistry / Q000382:microbiology*; D015003:Yeasts / Q000254:growth & development / Q000302:isolation & purification; D003313:Zea mays / Q000737:chemistry / Q000382:microbiology*