Comparison of the effects of extraction method and solvents on biological activities of phytochemicals from selected violet and blue pigmented flowers

Abstract

The flowers of many plant species are characterized by intense color and richness of bioactive compounds. They can be their valuable and curious sources that are worth extracting with the highest possible efficiency. The study compares the effects of different extraction methods and ultrasound (US) treatment on the physicochemical properties of dried petals of Malva sylvestris (MS), Clitoria ternatea (CT), Centaurea cyanus (CC), and Trifolium pratense (TP). The petals were ground and then extracted by three methods: (1) with H2O, (2) with 70% methanol, (3) with 70% methanol + acetic acid solvents, additionally used US. Measured: color parameters in CIEL*a*b* system; total antioxidant activity (TAA) referred to the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals activity; total phenolic content (TPC) by the Folin-Ciocâlteu method; total anthocyanin content (TAC) by the pH differential method. No specific differences in color parameters founded. The highest TAA (in % of DPPH reductive- MS: 87.86; CT: 62.56; CC: 72.04; TP: 82.99), TPC (in mg gallic acid equivalent/100 g of sample- MS: 1072.86; CT: 849.85; CC: 912.07; TP: 873.77), and TAC (in mg of cyanidin-3-glucoside/100 g of sample- MS: 747.79; CT: 226.46; CC: 267.53; TP: 234.77) was reached by method (3). US treatment increased the effect.