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Effect of high hydrostatic pressure treatment on the viability and acidification ability of lactic acid bacteria

Giannoglou, Marianna, Katsaros, George, Moatsou, Golfo, Taoukis, Petros
International dairy journal 2019 v.96 pp. 50-57
Lactobacillus delbrueckii subsp. bulgaricus, Lactococcus lactis, Streptococcus thermophilus, acidification, cell viability, cheesemaking, cheeses, high pressure treatment, lactic acid, lactic acid bacteria, pH, starter cultures, temperature
The effect of high pressures of 100–450 MPa combined with temperatures of 20–40 °C on Lactobacillus delbrueckii subsp. bulgaricus ACA-DC0105, Streptococcus thermophilus ACA-DC0022 and Lactococcus lactis ACA-DC0049 cell viability and acid production ability was studied. The rates of decrease in pH and cell viability were estimated for all the process combinations studied. The viability and acidification ability of the cells depended on the process conditions. More intense process conditions resulted in a lower number of viable cells and simultaneous reduction of lactic acid production correlated to lower rates of decrease of pH. Lb. bulgaricus appeared to be the microorganism most resistant to pressure, while Lc. lactis the most sensitive. Similar behaviour was observed for the acidification ability of these microorganisms, with Lc. lactis being least able to decrease the pH value of cheese. The HP-treated strains could be used as adjunct starters for cheese production.