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

ABSTRACT

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.