Study of Survival During Drying of Bacterial Cells of Starter Culture for Probiotic Fermented Milk Drinks

Five proprietary variants of bacterial starter culture with the following species composition were studied: No. 1 – Lac. diacetilactis, Lac. cremoris, Lac. acidophilus, No. 2 – Lb. plantarum, B. adolescentis, No. 3 – Lac. cremoris, No. 4 – Lac. lactis, Lac. diacetilactis, Lb. plantarum, No. 5 – Lac. lactis, Lac. diacetilactis, Lb. cremoris. Survival was assessed immediately after freeze-drying and during storage after 30, 90 and 180 days. It was found that the lactococci included in the bacterial starter culture of variants No. 1, 3-5 after drying and during storage showed the maximum survival of bacterial cells. Their number varied within the limits: after drying – 3.3-6.5 × 10 9 CFU/g, after 180 days – 1.0-2.0 × 10 9 CFU/g. A high degree of survival was noted in L. acidophilus (variant No. 1) – the number of viable cells after drying, as well as after 180 days of storage at the level of 1.0×10 8 CFU/g. The total amount of probiotic microflora of Lb. plantarum and B. adolescentis bacterial starter culture (variant No. 2) after drying was 3.2×10 9 CFU/g, and after 180 days of storage 1.0×10 9 CFU/g. Both cultures showed high survival of bacterial cells. The number of Lb. plantarum (variant No. 4) after drying and during storage was only 1.0×10 6 CFU / g, but it should be taken into account that this culture in the starter composition is additional, while the dominant microflora is represented by lactococci.