RELATIONSHIPS BETWEEN CHEMICAL AND MICROBIOLOGICAL COMPOSITION OF COMMERCIAL PLAIN YOGURTS.

Ten commercial plain stirred yogurts, seven produced in Italy, two in Croatia and one in Germany, were analysed. Some relevant chemical characteristics were widely variable among the samples. As regards microbiological composition, Streptococcus thermophilus cells were always numerous, while great fluctuations were found in the Lactobacillus delbrueckii subsp. bulgaricus. A RAPD analysis was performed to evaluate the presence of genetic variability among isolates from different products and a panel test with ten non-trained persons was set up to evaluate some organoleptic characteristics. A statistical analysis conducted to highlight relationships among the parameters tested, revealed that product characteristics seem to be influenced more by the amount of bacteria, particularly Lactobacillus, than by strain diversity. [ABSTRACT FROM AUTHOR]