The objective of this study was to determine whether or not cells of the lactic acid bacteria, contained in the commercial dairy starter cultures, were able to survive in the environment simulating the conditions in small intestine and whether or not the presence of cholesterol impacted their viability. The material studied were seven strains of lactic acid bacteria (Lb. acidophilus, Lb. casei, Lb. delbrueckii subsp. bulgaricus, Str. thermophilus i Bif. animalis subsp. lactis), three yoghurt starter cultures, six cheese starter cultures, and three kefir starter cultures. The study consisted in culturing strains of lactic acid bacteria in model intestine juice without and with the addition of cholesterol, at 37ºC for 5 h, and in determining the count of lactic acid bacteria using a plate method prior to and after the incubation. Bacteria contained in the mesophilic, diary starter cultures showed a similar resistance to the conditions of the model intestine juice as thermophilic lactic acid bacteria, including the probiotic strains studied. The addition of cholesterol to the model intestine juice did not significantly impact the viability of lactic acid bacteria under investigation. No significant difference between the viability of Lactococcus sp., Str. thermophilus, and Lactobacillus sp. was reported.
lactic acid bacteria, starter cultures, viability, intestine juice