title: Selection of promising lactic acid bacteria as starter cultures for sourdough: using a step-by-step approach through quantitative analyses and statistics.
abstract: BACKGROUND
  The main goal of this research was to show how to use a qualitative assessment of some technological properties of lactic acid bacteria (LAB), combined with the evaluation of the growth index (GI), to select promising starter cultures for sourdough.
  
  
  RESULTS
  Fifty-four strains of LAB were isolated from a single factory, identified by molecular tools and studied for their growth as a function of NaCl (20, 40 and 65 g L(-1)), temperature (45, 15 and 10 °C), pH 9.2 and acidification in MRS broth. The growth was evaluated through absorbance and data were modelled as GI. GIs were used to build frequency histograms and to run a principal component analysis (PCA). In this way, six strains, identified as Lactobacillus plantarum and able to grow in a wide range of conditions (temperature, pH and salt) and/or able to decrease the pH by 1.77-2.0 units, were selected and tested in a model system (flour and water) to study the acidification after 24 h and their viability after 14 days.
  
  
  CONCLUSIONS
  The main result of this paper was to show how a simple step-by-step approach could be a useful tool to select promising starter cultures for sourdough. The method was based on (1) strain identification, (2) assessment of some traits through the GI, combined with simple statistical approaches (frequency histograms and PCA), and (3) preliminary validation in model systems.
authors.affiliation: Department of the Science of Agriculture, Food and Environment (SAFE), University of Foggia, Via Napoli 25, I-71122, Foggia, Italy.
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: Corbo
authors.forename: Antonio
authors.initials: A
authors.lastname: Bevilacqua
authors.forename: Daniela
authors.initials: D
authors.lastname: Campaniello
authors.forename: Barbara
authors.initials: B
authors.lastname: Speranza
authors.forename: Milena
authors.initials: M
authors.lastname: Sinigaglia
mesh_terms: D001939:Bread / Q000032:analysis / Q000382:microbiology*; D015169:Colony Count, Microbial; D005285:Fermentation; D005433:Flour / Q000032:analysis / Q000382:microbiology*; D005516:Food Microbiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000378:metabolism*; D048191:Lactiplantibacillus plantarum / Q000254:growth & development / Q000378:metabolism
chemical_list: D019344:Lactic Acid
keywords: growth index; lactic acid bacteria; model systems; promising strains; sourdough