Sensory and chemical evaluation of tea brews prepared with the assistance of ultrasound

ABSTRACT: The aim of the study was to evaluate sensory and phytochemical (polyphenols, flavonoids and caffeine) estimation of black and green tea brews obtained in an alternative way through brewing with the assistance of ultrasound. Brews produced with the application of sonication for 2 minutes and 1 minute were the most preferred by the sensory evaluation team. Evaluation of the brews in terms of component descriptors, i.e. fragrance, flavour and colour, was varied and depended on the kinds of tea and on the applied experimental factors. It was demonstrated that ultrasound have a significant effect on the extraction of active substances, i.e. polyphenols, flavonoids and caffeine, from black and green tea. The application of sonication caused a significant increase in the concentration of flavonoids (by ca. 29% and 73%), polyphenols (by ca. 34% and 41%) and caffeine (by ca. 51% and 60%) in the tea brews.