Chemical and microbiological characterization of kefir grains from different origins.

GARROTE, GRACIELA L; ABRAHAM, ANALIA G; DEANTONI, GRACIELA L

Journal Of Dairy Research

Lugar: Cambridge University Press; Año: 2001 vol. 68 p. 639 - 652

0022-0299

Summary. Chemical and microbiological composition of four Argentinean ke®r grains from different sources as well as characteristics of the corresponding fermented milk were studied. Ke®r grains CIDCA AGK1, AGK2 and AGK4 did not show signi®cant differences in their chemical and microbiological composition. In contrast, protein and yeast content of AGK3 was higher than in the other grains. Although grain micro¯ora comprised lactobacilli, lactococcus, acetic acid bacteria and yeast, we found an important difference regarding species. Lactococcus lactis subsp. lactis,ummary. Chemical and microbiological composition of four Argentinean ke®r grains from different sources as well as characteristics of the corresponding fermented milk were studied. Ke®r grains CIDCA AGK1, AGK2 and AGK4 did not show signi®cant differences in their chemical and microbiological composition. In contrast, protein and yeast content of AGK3 was higher than in the other grains. Although grain micro¯ora comprised lactobacilli, lactococcus, acetic acid bacteria and yeast, we found an important difference regarding species. Lactococcus lactis subsp. lactis,Lactococcus lactis subsp. lactis, Lactobacillus ke®r, Lactobacillus plantarum, Acetobacter and Saccharomyces were present in all types of ke®r grain. While Leuconostoc mesenteroides was only isolated from grains CIDCA AGK1 and Lactococcus lactis subsp. lactis biovar diacetylactis,, Lactobacillus plantarum, Acetobacter and Saccharomyces were present in all types of ke®r grain. While Leuconostoc mesenteroides was only isolated from grains CIDCA AGK1 and Lactococcus lactis subsp. lactis biovar diacetylactis,Leuconostoc mesenteroides was only isolated from grains CIDCA AGK1 and Lactococcus lactis subsp. lactis biovar diacetylactis,Lactococcus lactis subsp. lactis biovar diacetylactis, Lactobacillus parake®r and Kluyveromyces marxianus were only isolated from CIDCA AGK2 grains. All grains produced acid products with pH between 3±5 and 4±0. The apparent viscosity of AGK1 fermented milk was greater than the product obtained with AGK4. All fermented milks had inhibitory power towards Escherichia coli but AGK1 and AGK2 supernatants were able to halt the bacterial growth for at least 25 h. Grain weight increment in AGK1, AGK2 and AGK3 during growth in milk did not show signi®cant differences. Despite their fermenting activity, AGK4 grains did not increase their weight.and Kluyveromyces marxianus were only isolated from CIDCA AGK2 grains. All grains produced acid products with pH between 3±5 and 4±0. The apparent viscosity of AGK1 fermented milk was greater than the product obtained with AGK4. All fermented milks had inhibitory power towards Escherichia coli but AGK1 and AGK2 supernatants were able to halt the bacterial growth for at least 25 h. Grain weight increment in AGK1, AGK2 and AGK3 during growth in milk did not show signi®cant differences. Despite their fermenting activity, AGK4 grains did not increase their weight.±5 and 4±0. The apparent viscosity of AGK1 fermented milk was greater than the product obtained with AGK4. All fermented milks had inhibitory power towards Escherichia coli but AGK1 and AGK2 supernatants were able to halt the bacterial growth for at least 25 h. Grain weight increment in AGK1, AGK2 and AGK3 during growth in milk did not show signi®cant differences. Despite their fermenting activity, AGK4 grains did not increase their weight.Escherichia coli but AGK1 and AGK2 supernatants were able to halt the bacterial growth for at least 25 h. Grain weight increment in AGK1, AGK2 and AGK3 during growth in milk did not show signi®cant differences. Despite their fermenting activity, AGK4 grains did not increase their weight.