THE IMPACT OF ADDITION OF DIFFERENT TEA POWDERS ON THE BIOLOGICAL VALUE OF WHITE CHOCOLATES

Abstract

Chocolate, in addition to green tea and red wine, is considered to be one of the richest sources of bioactive compounds; however, white chocolates are very poor in polyphenolic components. Therefore, this work aimed at the determination and comparison of the addition of different types of tea to increase the content of polyphenols, flavonoids, phenolic acids, and antioxidant activity of white chocolates. In this study, we focused only on white chocolates supplied by Czech chocolate producing company. The content of total polyphenols was evaluated using the Folin-Ciocalteu reagent, the total content of flavonoids was measured using spectrometric assay based on a formation of colored flavonoid-aluminum complex, and the content of total phenolic acids was evaluated using Arnow's reagent. Antioxidant activity was measured by three different assays, which were DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activity, ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)) assay and reducing power method. The obtained results showed that plain white chocolate is a poor source of biologically active compounds and also antioxidant activity measured by different methods was found low. However, the addition of various kinds of teas to chocolates enhanced the amount of total polyphenols, flavonoids, and phenolic acids more than two times. This enrichment influenced also the antioxidant activity of the samples positively, which increased several fold. Best results were obtained with the addition of green teas.