This application note exhibits a detailed method for the determination of tannin in tea by photometry with fully automated METTLER TOLEDO Excellence Titrators and DP5 Phototrode™.
What Is Tannin?
Tannins are polyphenols commonly found in food and drinks, mainly tea. They have antioxidant, anticarcinogenic, antimutagenic, and antimicrobial properties and are, therefore, useful in the prevention and treatment of diseases. The economic importance of tannins to the leather industry led to the essentiality of tannin determination.
Photometric Determination of Tannin in Tea
Titrimetry, spectrophotometry, and chromatography are the most commonly used techniques to estimate tannin content. In this application note, the tannin content of tea samples is determined by photometric titration by titrating against potassium permanganate in the presence of indigo carmine as an indicator that gives a color change from blue to green and finally to yellow. A DP5 Phototrode™ can be used as a photometric indication at 590 nm to indicate the color change.
This Application Note Includes
- An introduction to the method
- Sample preparation and procedures
- Solutions and chemicals
- Chemistry
- Instruments and accessories
- Results and remarks
Method files (.lmt and .xml) are also included for direct import and implementation of the instrument.
Download our free application note and benefit from our experience in determining the tannin in tea by photometric titration using the Excellence titrators T5/T7/T9 and DP5 Phototrode™.
