Cold storage conditions microbial activity of lactic acid

Coliform bacteria, molds and yeasts was not detected in any of the samples studied. 1 ± 5 show Figs viability of lactic acid microorganisms and changes in pH. The two different types of yogurt Storage temperature, in about two months. In all cases, at the beginning of the experiment, indicating that different
Total count of yogurt lactic acid Lactic acid than 108 fitness. s. Streptococcus number Chinensis was higher than the delbrueckii subsp. Yoghurt in sets (Figure 1) the level of reduction About 1 log cycle less than 60 days in streptococci, while the cell viability 12C dramatic impact force, and it is off almost zero. On the other hand, lactic acid powder born after Viability, showing just a very steady decline at two temperatures (3 and 6 log cycles after 60 days
, Respectively, 6 and 12C). The initial pH value (together 4.3) stable at less than in the rapid rise (in the whole Experiment), but it decreased to 4.0 in 12 degrees Celsius in the environment. Evolution of lactic acid microorganisms
SkimmedSet yogurt (Figure 2) shows the six degrees of streptococci in order to continue to survive, even Enough to breed, and their numbers increased slightly from their initial fitness level gy1 109). However, at 12C The initial cell number remains the same as about 40 days, and then they rapidly degraded, to 5X105 CFU g?1 refrigerated storage. In such products, lactic acid after increasing its population in order logs An initial 10 days cold storage, maintenance 5X108 CFU g?1 at 12C in the next 15 days. Later in the
Fitness gy1 declining to 105 at the end of the storage period. On the other hand, the l. Delbrueckii As subsp. Than statistics stabilized at 5X107 CFU g?1 one day 15 - 45 of the, but the count Reduce future. The initial pH value after 10 days (chapter 4.7) fell to 42.5, then it remains Changed.