title: Natural milk cultures for the production of Argentinian cheeses.
abstract: Samples (32) of natural milk cultures used in the Santa Fe, Argentina, area for soft and semihard cheese production were examined. The microbial composition (including lactic acid microflora characterization) and technological parameters (acidifying and proteolytic activities) were evaluated. The cultures contained mainly thermophilic lactic acid bacteria, identified as Streptococcus salivarius subsp. thermophilus (96.8% of the total strains) and Enterococcus spp. The strains showed a low proteolytic activity. The isolates of S. salivarius subsp. thermophilus exhibited a widespread phage resistance. The nonlactic microflora comprised coliforms, yeasts, spore-forming bacteria and lactate fermentative bacteria. The samples showed an acidity level from 0.38 to 0.69% lactic acid (pH from 4.25 to 5.75). The acidifying activity was optimal at 45 degrees C. The advantages and disadvantages of the employment of natural milk starters are discussed.
authors.affiliation: Programa de lactología Industrial, Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero, Santa Fe, Argentina. jorreinh@figus.unl.edu.ar
authors.forename: J A
authors.initials: JA
authors.lastname: Reinheimer
authors.forename: A G
authors.initials: AG
authors.lastname: Binetti
authors.forename: A
authors.initials: A
authors.lastname: Quiberoni
authors.forename: N B
authors.initials: NB
authors.lastname: Bailo
authors.forename: A C
authors.initials: AC
authors.lastname: Rubiolo
authors.forename: G
authors.initials: G
authors.lastname: Giraffa
mesh_terms: D000818:Animals; D001118:Argentina; D001419:Bacteria / Q000302:isolation & purification*; D002611:Cheese; D015169:Colony Count, Microbial; D003470:Culture Media; D016983:Enterococcus / Q000302:isolation & purification / Q000502:physiology; D005511:Food Handling / Q000379:methods*; D005525:Food-Processing Industry; D006863:Hydrogen-Ion Concentration; D008892:Milk / Q000382:microbiology*; D010957:Plasmids; D013291:Streptococcus / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology; D013696:Temperature
chemical_list: D003470:Culture Media