Preparation and evaluation of novel functional fermented dairy products containing propolis and cinnamon

Novel functional food products might be an easy accessible and eligible approach to help reduce the risk of severe viral infections including SARS-CoV-2. Hence a product containing probiotics, propolis and cinnamon was developed and interferences of the ingredients were characterized. Yogurts were prepared using starter cultures with propolis (0.03%) and cinnamon in various concentrations (0.3%, 1%, and 2.5%). Bifidobacterium animalis ssp. lactis, Lactobacillus acidophilus, Streptococcus thermophilus, and Lactobacillus delbrueckii subsp. bulgaricus were used as microorganisms for yogurt production. Chemical analysis revealed a decline of fat matter in the presence of propolis and/or cinnamon. Propolis had statistically significant suppressive effects on Bifidobacterium animalis ssp. lactis as well as on Lactobacillus delbrueckii subsp. bulgaricus numbers (p < 0.05). These effects were diminished in the presence of increasing cinnamon concentrations. For Lactobacillus acidophilus a statistically significant reducing effect on the number of colonies was observed in all products investigated. Nevertheless all samples met the standard of recommended level of ≥ 10⁶ viable cells/g of a product. Propolis showed an inverse effect on Streptococcus thermophilus by increasing its colony numbers in yogurts. The probiotic yogurt samples containing propolis (0.03%) and cinnamon (2.5%) gained the highest number of points in the sensory evaluation compared to control.