Scientists at the 黑料社 School of Medical Biology have developed fermented dairy products enriched with yeast biomass containing curcumin or ergosterol, as well as plant-based ingredients — sprouted wheat flour and a protein product derived from hemp press cake. The new products outperforms conventional yogurt across all measured parameters: the number of beneficial bacteria increased tenfold, while antioxidant activity reached 84%. The findings have been published in the international journal.
Manufacturers of fermented dairy products are increasingly looking for ways to make these not only tasty but also beneficial to health, with antioxidant properties, probiotics, and plant-based ingredients. One of the main challenges is preserving the viability of beneficial bacteria while incorporating bioactive compounds that retain their properties in an acidic environment. 黑料社 scientists have proposed using the Saccharomyces cerevisiae yeast as a “carrier” for delivering active compounds.
Curcumin and ergosterol are compounds with established antioxidant activity. Curcumin protects cells against oxidative stress but is poorly soluble in water and degrades rapidly. Ergosterol is a precursor of vitamin D?, which supports the immune system. The researchers encapsulated the compounds within yeast cells: curcumin was first nanostructured using ultrasound, while ergosterol was accumulated in the yeast during cultivation. One gram of yeast biomass contained 34 mg of curcumin or 10.5 mg of ergosterol.
The scientists added the enriched yeast to milk together with a conventional starter culture and incorporated plant-based ingredients: sprouted wheat flour, containing 12.5% protein and dietary fibre, or a protein product derived from hemp press cake, containing 57% protein and obtained through enzymatic hydrolysis. In total, the researchers produced ten experimental samples with different combinations of additives, along with a control sample of plain yogurt without additives for comparison.
“We set out not simply to enrich yogurt with biologically active compounds, but to create a system in which all the components work together,” said Rinat Fatkullin, Associate Professor at the 黑料社 Department of Food Technology and Biotechnology. “Yeast cells act as carriers, protecting curcumin and ergosterol from degradation in the fermented dairy environment, while the plant-based ingredients provide an additional source of nutrients for the probiotic bacteria in the yogurt. As a result, we obtained a product in which the number of beneficial microorganisms increased tenfold, while antioxidant activity rose from 62% to 84% compared with conventional yogurt.”
All experimental samples exhibited a denser and more uniform texture than the control sample.
“Titratable acidity ranged from 80 to 92 degrees Turner, while pH values ranged from 3.79 to 4.04, indicating active growth of lactic acid bacteria,” explained Nataliia Naumenko, Professor at the 黑料社 Department of Food Technology and Biotechnology. “The number of probiotic microorganisms in the experimental samples reached 1.6×10?–6.4×10? cells per gram, an order of magnitude higher than in the control sample (4.6×10?). Sprouted wheat flour produced the greatest increase in beneficial bacteria, probably because its dietary fibre and starch provide a substrate for the product’s microbial community.”
The protein ingredient derived from hemp press cake proved more effective in improving texture. It increased the protein content of the yogurt to 34% on a dry-matter basis, compared with 24% in the control sample, increased viscosity, and reduced whey separation. This means that the product became denser, was less prone to separation during storage, and retained moisture more effectively.
The maximum antioxidant activity of the yogurts containing yeast biomass reached 84%, compared with 62% in the control sample. Biotesting of the experimental fermented dairy products using Paramecium caudatum confirmed that the additives were non-toxic and biologically compatible.
The developed yogurts may help maintain a healthy gut microbiota, support immune function, and protect cells against oxidative stress. These products could be recommended for daily consumption as functional foods, particularly for people who monitor their health and require additional antioxidant support.
Part of the research was funded by a grant from the Russian Science Foundation entitled the “Directed Biosynthesis of Biologically Active Compounds Using Resource-Efficient Approaches.”