Ultrasound-Assisted Extraction as a Technique for Preparing Improved Infusions as Functional Beverage Bases

Right after water, tea is one of the most popular beverages in the world. The composition of a tea drink is determined by, among other things: the degree of fermentation and the fineness of the tea leaves, as well as the brewing time and temperature. The purpose of this study was to verify the hypothesis that the extraction of selected elements from dried tea during infusion preparation was improved by using ultrasound under laboratory conditions. The effect of increasing the extraction time was also analyzed. The effectiveness of ultrasound was evaluated by measuring the content of selected elements in the extract of teas that were treated with ultrasound compared to a control group. The effectiveness of the application of ultrasound was evaluated by measuring the content of individual elements at intervals of 1 min, 5 min and 10 min comparing the application of ultrasound with the classical technique of tea brewing. In addition, the results were related to measurements of the amounts of overall concentrations of selected ions after the dried tea mineralization procedure. Samples of extracts and mineralizates were analyzed for elemental composition using an ICP-OES iCAP Dual 6500 Thermo® spectrometer. The use of ultrasound was shown to have a positive effect on the extraction process, and the efficiency of the process depended on the tea variety and the extraction time. The percentage of extraction relative to the results of the total amount of extracted ions was also calculated. Analyzing the effect of ultrasound on the leaching of minerals from tea leaves during infusion preparation is another step toward optimizing the tea brewing extraction process and a way to improve the nutritional value of tea infusions as a functional beverage base. The application of ultrasound in the extraction process of tea infusions may be a good solution to support traditional methods of extracting infusions for both research and technological purposes.