Use of plasmolysed yeast to encapsulate and enhance the bioavailability of plant antioxidants

Abstract. The yeast Saccharomyces cerevisiae is widely used in many fermentative processes of food production. At the same time, the spent yeast biomass obtained after production processes generates significant amounts of waste. Thus, in the brewing industry residual brewer's yeast is the second largest volume of waste, which is about 3% of the volume of brewed beer. Utilization of these wastes is rather complicated and requires additional costs from the enterprises. Under these conditions, the directions of additional utilization of spent yeast mass are of high interest. One of such directions can be the use of plasmolysis of spent yeast and its further use for encapsulation of biologically active substances. Among biologically active compounds, plant polyphenols – substances with pronounced antioxidant properties – occupy an important place. Scientific novelty. This study examines dihydroquercetin, rutin and curcumin in their original and nanostructured forms. For these compounds an extensive list of pharmacological properties such as anti-inflammatory, antioxidant, capillaroprotective and others has been established. At the same time, these compounds are characterized by a low level of bioavailability. The purpose of the study was to investigate the possibility of using spent, plasmolysed cells of brewer's yeast Saccharomyces to encapsulate plant polyphenols: dihydroquercetin, rutin and curcumin, and to evaluate the effect of such an approach on the bioavailability of biologically active substances in an in vitro digestion model. Results. As a result of these studies, it was found that plasmolysed yeast cells are able to act as a “delivery system” of plant antioxidants. Using the proposed approaches, it is possible to achieve an encapsulation efficiency of approximately 57–64 %, provided that the polyphenols are ultrasonically nanostructured beforehand. Analysis of the potential bioavailability of encapsulated forms of plant antioxidants in an in vitro gastric digestion model showed that the technology of encapsulation into yeast cells allowed to ensure the preservation of plant antioxidants about 80 %. In comparison with the initial forms of biologically active substances, encapsulation allowed to provide an increase in bioavailability by about 30–40 %.