EFFECT OF HIGH PRESSURE ON MICROFLORA AND SENSORY CHARACTERISTICS OF YOGHURT.
More details
Hide details
Publication date: 2005-03-31
Pol. J. Food Nutr. Sci. 2005;55(1):79-84
KEYWORDS
ABSTRACT
The effects of the high pressure treatment (400-600 MPa) on microflora and sensorial characteristics of yoghurts was investigated. The experiment indicated that the pressures employed had no significant effect on the acidity of yoghurts. Changes in microbial survivability were related to the applied pressure and to the acidity of pressurized yoghurts. It was confirmed that Lactobacillus delbrueckii ssp. bulgaricus was more sensitive to pressurisation than Streptococcus thermophilus. Yoghurt processed at a pressure of 550 MPa maintained its beneficial sensorial characteristics longer than the non-pressurized yoghurt, during storage for 4-weeks at refrigerating (4oC) and room (20oC) temperatures. The pressure prevented the post-acidification in the yoghurts examined. The number of bacteria in the pressurized yoghurt stored at 4oC maintained under the therapeutic minimum level 106 of cfu/mL. The addition of fruit preparation beneficially affected the consistency of the pressure-treated yoghurt. The survivability of bacteria was higher about one order of magnitude in the pressurized fruit yoghurt than in the plain yoghurt.