Lactobacilli Strains with Targeted Technological Properties in Sour-Cream Butter Biotechnology

Dairy products can be fortified with new valuable strains of probiotic lactobacilli. This research tested two new lactobacilli strains for prospects in sour-cream butter production. The lactobacilli strains of Lactobacillus plantarum and Enterococcus hirae were selected at the Research Institute of Biotechnology, Gorsky State Agrarian University. The study also involved a symbiotic starter based on these strains, cow’s milk cream, and sourcream butter. The quality indicators were assessed using a Klever milk analyzer and a set of standard methods: physicochemical indicators for the cream, clot formation rate and pH for the lactobacilli, and sensory, physicochemical, and microbiological indicators for the butter. The study revealed the sensory and physicochemical profile of the cream, the curding rate and the pH rate of the sour-cream during cultivation, and the physicochemical parameters of the resulting sour-cream butter. It took the symbiotic starter of L. plantarum and E. hirae (1:1) 6 h to curd at an acidity of 68.00 °T; L. plantarum curded in 6 h at 56.00 °T; E. hirae curded in 7 h at 65.00 °T. The maximal acid-forming capacity of L. plantarum was 323 °T (6 days of incubation), that of E. hirae was 170 °T (5 days), and that of the symbiotic culture was 220 °T (4 days). The technology of producing sour-cream butter included pasteurization, cooling, heating, adding starter (L. plantarum and E. hirae), churning, processing butter granules, and shaping. The sour-cream butter sample produced with the symbiotic starter contained 25.2% moisture and 71.4% fat; it had a caloric value of 665.0 kcal. It was yellow, dense, and shiny, with a characteristic sour-cream taste and smell. The experimental sour-cream butter demonstrated excellent sensory indicators and could be recommend for industrial production with strains of L. plantarum and E. hirae in a ratio of 1:1.