Effect of the encapsulation process on the preservation of the antioxidant properties of flavonoids

The objective of this study was to explore the effect of flavonoid encapsulation technologies on their antioxidant properties. The most studied representatives of flavonoids - taxifolin and rutin, which are known strong antioxidants, were selected as the objects of research. For these compounds, an extensive list of pharmacological effects has been established that determine the possibility of their use as functional food ingredients. At the same time, being chemically labile substances, taxifolin and rutin are prone to oxidative degradation and chemical transformations during digestion, which can lead to a significant decrease or complete loss of bioactive properties. A possible solution to these problems may be the use of encapsulation technologies. The research evaluated the possibility of using two approaches to encapsulation: for rutin-complex coacervation using gelatin and pectin; for taxifolin - encapsulation in β-cyclodextrin. For the encapsulation process, methods of physical influence were used: taxifolin was encapsulated at a speed of 200 rpm for 3 hours at a temperature of 40 °C, and rutin was carried out under mechanical mixing conditions at a speed of 500 rpm for 15 minutes. The efficiency of the approaches was evaluated by indicators of total antioxidant activity (DPPH method) and calculation of the bioactivity index using the in vitro digestion model. The results of determining the total antioxidant activity showed that the initial forms of flavonoids are characterized by pronounced antioxidant properties in the range of 65-85 %. The encapsulation of flavonoids resulted in a significant decrease in the values of total antioxidant activity, by about 19.3 % for taxifolin and 55.4 % for rutin, possibly due to the use of different encapsulation approaches. Evaluation of potential bioactivity in the in vitro model showed the feasibility of using encapsulation to protect flavonoids during digestion and ensure the preservation of their antioxidant properties. The values of bioactivity indices for the encapsulated forms were 72.4 and 80.0 % for taxifolin and rutin, respectively, against 51.2 and 41.5 % for the initial forms of taxifolin and rutin.