The Effect of Water Mineralization on the Extraction of Active Compounds from Selected Herbs and on the Antioxidant Properties of the Obtained Brews.

Jakub Wyrostek,Radosław Kowalski

doi:10.3390/foods10061227

Jakub Wyrostek, Radosław Kowalski

Open Access

https://doi.org/10.3390/foods10061227

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Abstract

The objective of the study was to analyze the effect of total content of minerals in waters on the effectiveness of extraction of polyphenols and flavonoids and on the antioxidant properties of brews from leaves of green and black tea, leaves of peppermint, chamomile inflorescences, leaves of sage, and flowers of lavender. The process of brewing was conducted at an initial temperature of 95 °C, under cover, for 15 min, with the use of 10 waters differing in terms of mineral components. The content of total polyphenols and total flavonoids was determined in the brews obtained. The antioxidant properties were assayed with the use of stable DPPH radicals and Ferric Reducing Antioxidant Power (FRAP) reagent. A significant effect of water mineralization on the extraction of phenolic compounds and on the antioxidant properties of the brews obtained was observed. In the majority of cases, the highest concentrations of polyphenols and flavonoids were obtained in brews prepared with the use of deionized water and waters with medium levels of mineralization. It was also demonstrated that there was a significant reduction of antioxidant properties in brews prepared with the water that had the highest level of mineralization (2896 ppm), at 70% and 93%, respectively, for green and black teas.

Highlights

In the case of leaves of peppermint (Figure 4), in brews prepared on the basis of lowmineralized waters higher concentrations of polyphenols and flavonoids were assayed, compared to brews prepared with the use of high-mineralized waters
The obtained statistically lower concentrations of biologically active compounds from the group of polyphenolics and flavonoids in brews prepared with the use of waters with high levels of mineralization, compared to brews obtained with the use of waters with lower mineralization levels, correspond with the results obtained by other authors who indicate that during the extraction of those components from tea Camelia sinensis (L.) Kuntze so-called “tea cream” can be formed, i.e., a sediment that forms during the cooling down of tea brew as a result of complexation of caffeine with theaflavins or thearubigins [20]
Summing up the above research results, one can conclude that the level of mineralization of water used for the preparation of popular tea or herbal brews has an impact on the process of extraction of bioactive components such as polyphenols and flavonoids, and on the antioxidant activity of such brews

Summary

Introduction

Water is an important component in the human diet as it performs a number of various functions which are essential for correct functioning of the organism. It is used for the preparation of various foods and dishes, including drinks, among which brews of tea, coffee or herbs occupy a significant position [1]. The composition of waters available on the market and the level of their mineralization have an impact on the level of their importance as a source of valuable minerals. An adequate supply of minerals, including calcium and magnesium, is very important for proper functioning development and functioning of the human body, because they play important physiological roles, e.g., they are the material for bones, they affect the course of metabolic processes and regulation of water and electrolyte balance [2]

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