# Comprehensive Analysis of Brewed Tea: Boron Content, Total Antioxidant and Oxidant Capacity, Oxidative Stress, and pH value

## TL;DR

This study analyzes the health-related properties of brewed tea in Türkiye, finding it safe and beneficial for daily boron intake, though acidic enough to potentially harm tooth enamel.

## Contribution

The study provides novel data on boron content, antioxidant capacity, and pH levels in Turkish teas, highlighting their health implications.

## Key findings

- Teas contain an average of 11.73 mg/L boron, with domestic teas having lower boron than imported ones.
- Approximately 30% of boron transfers into brewed tea, and pH values range between 4–5.
- Teas have an oxidative stress index less than 1, indicating good antioxidant effects.

## Abstract

Tea is widely recognized as the most consumed beverage in the world after water. In recent years, the connection between tea and health has gained growing attention as a significant research topic. In this study, we evaluated the relationship between tea and health by analyzing the boron content, total antioxidant capacity (TAC), total oxidant capacity (TOC), oxidative stress index (OSI), and pH levels of teas commonly consumed in Türkiye. A total of 42 samples were created from various tea brands and different tea types that are widely consumed in Türkiye. The determination of boron in pulverized and brewed tea samples was carried out using the carminic acid method. Additionally, boron transfer was determined in brewed teas. Brewed tea samples were also examined in terms of pH, TAC, TOC, and OSI. It was determined that all teas contained an average of 11.73 mg/L boron, the amount of boron in domestic teas was lower than in imported teas. It was determined that boron transfer into brewed tea was approximately 30%. The pH values ranged between 4–5. No differences were detected in terms of TAC, TOC, and OSI. Our research shows that tea consumption is safe in terms of boron levels and helps meet daily needs. The OSI of teas is less than 1, so their antioxidant effects can be considered quite good. However, it should be noted that excessive tea consumption can lead to the demineralization of tooth enamel due to low pH levels.