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 non-sporing 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. (C) 2012 Elsevier Ltd. All rights reserved.
keywords
STREPTOCOCCI; ENUMERATION; IDENTIFICATION; DOUGHS; AGAR; CORN
subject category
Biotechnology & Applied Microbiology; Food Science & Technology; Microbiology
authors
Rocha, JM; Malcata, FX
Groups
acknowledgements
Several members of the Regional Directorate of Agriculture of Entre-Douro-e-Minho (DRAEDM, Portugal) and several local farmers are hereby gratefully acknowledged for their cooperation in supplying samples for analysis. Financial support for author J. M. R. was provided by a Ph.D. fellowship within program PRAXIS XXI - ref. PRAXIS XXI/BD/16060/98, administered by Fundacao para a Ciencia e a Tecnologia (Portugal) and supervised by author F. X. M. Partial financial support was received within program PAMAF - IED, through research grant