Biochemical and microbiological characterization of artisanal 'Penamellera' cheese:: analysis of its indigenous lactic acid bacteria

Three batches of artisanal 'Penamellera' cheese manufactured at different times of the year have been analysed. Biochemical parameters fluctuated widely between batches due to unpredictable changes in temperature and humidity during manufacture. The profile of volatile compounds in 'Penamellera' cheese was found to be simple, with ethanol, 2-heptanone and 3-methyl butanol as the predominant components. The microbiota of the three batches was independently monitored on the surface and in the interior of the cheeses through a 30 d ripening period. Lactococci became dominant early after manufacture and remained so during ripening (they almost reached values of 10(9) cfu g(-1)). Most of the isolates were classified as Lactococcus lactis subsp. lactis. Lactobacilli remained at a subdominant level (around 5.0 x 10(7) cfu g(-1)) and a high proportion of heterofermentative strains was found. Dextran-producing Leuconostoc isolates were found at a level of approximately 10(6) cfu g-l. Strains of lactococci were examined for several technologically important traits as a first approach to select suitable strains to be used in starter cultures. (C) 2000 Elsevier Science Ltd. All rights reserved.