Use of Micronization and Complex Coacervation to Preserve Antioxidant Properties of Flavonoids

The plant flavonoids taxifolin and rutin are among the best known and best studied antioxidants. In addition to their antioxidant properties, other pharmacobiological properties have been established for these substances. At the same time, taxifolin and rutin are chemically labile. They are prone to oxidative degradation and have poor water solubility. Under conditions of their real consumption, all this can lead to a significant reduction or complete loss of bioactivity of these flavonoids. Flavonoid modification and encapsulation techniques can be used to overcome these barrier factors. The use of micronization process for taxifolin and rutin allows changing the lipophilicity values of antioxidants. For micronized taxifolin, the log P value is 1.3 (1.12 for the control forms), and for rutin, it was 0.15 (-0.64 for the control forms). The antioxidant activity of micronized flavonoids has increased about 1.16 times compared to control forms. The present study evaluates the possibility of using encapsulation of premyconized flavonoids by complex coacervation, in order to preserve their antioxidant properties. The results of an in vitro digestion study show that the encapsulated forms of antioxidants retain their bioactivity and bioavailability better than their original forms. The bioavailability indices for the encapsulated forms of flavonoids are more than 1.6 times higher than for their original forms. The digested fractions of the encapsulated properties reveal better antioxidant properties than their original forms in in vitro tests evaluating the antioxidant properties on cultures of the protozoan Paramecium caudatum and human neuroblastoma SH-SY5Y cells. Encapsulated rutin indicates the highest activity, 0.64 relative to PMA. Thus, the studies represent the feasibility of using encapsulation to protect flavonoids during digestion and ensure the preservation of their antioxidant properties.

The Influence of Flavonoid Dihydroquercetin on the Enzymatic Processes of Dough Ripening and the Antioxidant Properties of Bread

Bread is an integral part of the diet of the world population. Development of bread enriched with biologically active substances, including antioxidants, could be good nutritional support for human health. Among well-studied antioxidants, we can highlight dihydroquercetin, a flavonoid with outstanding antioxidant properties, such as anti-inflammatory activity, immunostimulatory properties, anti-cancer properties, and others. At the same time, the technology of bread enrichment must consider the possible negative effects of the additive on the technological processes and properties of the final product. The present work was carried out to evaluate the effect of dihydroquercetin on the enzymatic processes occurring during dough maturation and the antioxidant properties of the finished bread. Dihydroquercetin was added in amounts of 0.05 g, 0.07 g, and 0.1 g per 100 g of wheat flour and fermented with commercial baker’s yeast (Saccharomyces cerevisiae). The kinetics of pH and total titratable acidity (TTA) during dough fermentation showed that dihydroquercetin caused slight slowing of enzymatic processes. However, the dosage of dihydroquercetin did not cause statistically significant changes in the yeast concentration, which reached a level of 108 KOU/g after 2 h in all dough samples. Loss of dihydroquercetin during fermentation was established at a level of 20–25%. At the same time, an increase in the total amount of flavonoids in the dough after 2 h of fermentation and an increase in values of antioxidant activity were noted. The antioxidant properties of the bread also increased when it was enriched with dihydroquercetin (about 3.5–4 times) despite the fact that the total quantitative loss of antioxidant in the technological process was considerable (about 40%). A protective effect of the bread matrix on flavonoids during digestion was shown. Dihydroquercetin loss was about 25% regardless of the amount applied. This work clearly showed that addition of dihydroquercetin to a bread formulation represents a promising strategy for increasing the antioxidant properties of bread.

Increasing the Efficiency of Taxifolin Encapsulation in Saccharomyces cerevisiae Yeast Cells Based on Ultrasonic Microstructuring

The aim of the present study was to investigate the possibility of encapsulating the plant antioxidant taxifolin in the living cells of the yeast Saccharomyces cerevisiae. Taxifolin is an unstable substance prone to oxidative degradation and actively enters into chemical reactions with a decrease or loss of bioactive properties. To minimize these problems, the use of encapsulation technology has been proposed. The cells of the yeast Saccharomyces cerevisiae have been chosen as a protective material for taxifolin. The encapsulation process was carried out using simple diffusion methods in living Saccharomyces cerevisiae cells in a thermostatically controlled shaker for 24 h. The aim of the study was to evaluate the effect of preliminary microstructuring of taxifolin on the efficiency of its encapsulation in yeast cells. The microstructuring process was carried out using low-frequency ultrasonic cavitation exposure for 7 min with a frequency of 22 ± 1.6 kHz and a power of 600 W/100 mL. The studies confirmed the feasibility of the proposed approach. It was found that microstructuring changes the dispersed composition of taxifolin particles and their morphology in solution and also increases the value of the antioxidant activity. Preliminary microstructuring of taxifolin increases the efficiency of its encapsulation in Saccharomyces cerevisiae yeast cells by 1.42 times compared to the initial form. A positive dependence of the growth of the encapsulation efficiency on the duration of the process was also established. Thus, the conducted studies confirmed the advantage of encapsulation of taxifolin in living cells of the yeast Saccharomyces cerevisiae in microstructured form.

Bioavailability and Safety of Dihydroquercetin (Review)

Dihydroquercetin (DHQ) is a bioflavonoid with high antioxidant, capillary-protective, and anti-inflammatory activity. DHQ has previously been used for treating Middle East respiratory syndrome coronavirus (MERS-CoV) infection and is currently considered a potential regulator of oxidative stress as part of COVID-19 multipurpose therapy. DHQ has a high safety profile but low bioavailability that limits its use. Innovative techniques (liposomization, crystal engineering, etc.) can be used to increase its bioavailability.