Research on the technology of black and green tea extracts with antioxidant activity production: determination of the effect of the degree of grinding of the initial raw material on the removal of antioxidant substances

The aim of the study was to select the degree of grinding for black and green tea, providing the highest levels of phenols, flavonoids, tannins, antiradical activity according to the DPPH method and restoring power according to the FRAP method. Research objectives are obtaining raw materials with a grinding degree of 0.5; 1.0; 1.6 mm; obtaining extracts of black and green tea using water; determination of phenolic substances, flavonoids, tannins, antiradical activity by the DPPH method, restoring force by the FRAP method in black and green tea extracts with a grinding degree of 0.5; 1.0; 1.6 mm; determination of the degree of grinding, when using which the largest amount of antioxidant substances is extracted. The objects of the study were black and green tea extracts obtained using one type of solvent - water and three degrees of grinding: 0.5; 1.0; 1.6 mm. The degree of grinding of black and green tea leaves has been determined, which makes it possible to extract antioxidant substances from black and green tea as fully as possible. The maximum amount of phenolic substances (784 and 1324 mg (HA)/100 g), flavonoids (437 and 651 mg (K)/100 g), tannins (98.2 and 119.7 mg catechin / 100 g) were extracted from black and green tea when grinding 0.5 mm. The highest index of restorative power was observed in extracts of black and green tea with a grinding of 0.5 mm (14.27 and 13.96 mmol Fe2+/kg). When milled with 0.5 mm, black and green tea extracts exhibited the least antiradical activity (Ec50 = 3.7 mg/cm3 and Ec50 = 3.3 mg/cm3, respectively). We recommend grinding tea 0.5 mm as the most suitable for obtaining extracts from black and green tea with a high level of the studied indicators.