Production of set-type probiotic and prebiotic yogurt-like products using Enterococcus faecium and Enterococcus faecalis strains in combination with pumpkin waste.

This study investigated the effect of pumpkin powder (2 %, 4 %, and 6 %) and Enterococcus faecium and Enterococcus faecalis probiotics on the physicochemical, microbiological, and sensory properties of yogurt samples during 28 days of storage at 4 °C. The prebiotic effect of pumpkin powder (Cucurbita pepo) and the probiotic effect of Enterococcus faecium and E. faecalis were determined. Adding pumpkin powder to yogurt did not significantly alter the pH, acidity, fat, protein, and ash content (p > 0.05). Water holding was not changed during the storage time in the samples of probiotic yogurts, but as the pumpkin powder content increased, the water holding capacity also increased (p < 0.05). This situation did lead to a reduction in syneresis (p < 0.05). The lowest gumminess value at the end of storage was found in the D2 sample (p < 0.05), and the highest adhesiveness value was found in the D4 sample (p < 0.05). Furthermore, throughout the 28-day storage period, E. faecium and E. faecalis maintained a live cell count of ≥6 log CFU g-1 in the probiotic product. As a result of the statistical evaluation, there was a decrease in E. faecium in the D4, S2, and S4 samples, and then it increased again (p > 0.05) during the storage time. As a result of the statistical evaluation, it was determined that the smell, consistency in the spoon, consistency in the mouth, flavor, and acidity changes during the storage were not substantial (p > 0.05). In conclusion, it was found that pumpkin, a byproduct of the pumpkin seed industry, has the potential to act as a prebiotic and improve the properties of dairy products. Additionally, the study suggests that E. faecium and E. faecalis strains could be suitable for probiotic yogurts.

Assessment of the Probiotic Properties of Yarrowia lipolytica Isolated from Cold-Pressed Olive Oil.

This research aimed to identify the probiotic features of Yarrowia lipolytica strains isolated from olive oils in Turkey. The in vitro survival capabilities of Y. lipolytica strains in gastric and pancreatic solutions were assessed. The hydrophobicity of Y. lipolytica strains was determined to be between 25.8% and 46.08% for xylene, 22.5% and 45.85% for chloroform, and 14.83% and 37.09% for ethyl acetate. In addition, auto-aggregation values were measured as 11.07-60.35%; 16.28-67.70% and 42.89-85.21% after 2, 4 and 24 h of incubation, respectively. The Y. lipolytica strains tested in this study demonstrated aggregation ability against the pathogens Escherichia coli ATCC 25922, Salmonella typhimurium ATCC 14028, Staphylococcus aureus ATCC 25923 and Listeria monocytogenes ATCC 7644. Antibiotic resistance and hemolytic activities were also checked to ensure the safety of the Y. lipolytica. Cholesterol removal by Y. lipolytica strains ranged from 12.30% to 47.42%, and their free radical scavenging activity varied between 2.85% and 39.10%. Out of 13 Y. lipolytica samples from 10 different olive oil sources, Y. lipolytica Y6, Y7, and Y11 exhibited the best strains with probiotic potential properties. This study discovered that Y. lipolytica with probiotic properties can be isolated in olive oil samples, a finding that has not been previously documented in the literature and may have potential industrial applications.