[Identification of tea from different regions using X-ray fluorescence]

Area of Science:

• Analytical Chemistry
• Chemometrics
• Materials Science

Context:

• The proliferation of counterfeit tea products poses a significant threat to the reputation and economic value of authentic, origin-specific teas.
• Existing authentication methods may be insufficient to reliably distinguish teas based on geographical origin.
• Heavy metal content in tea leaves is known to vary based on geographical factors and cultivation practices.

Purpose:

• To develop and validate a robust method for identifying the geographical origin of tea samples.
• To differentiate authentic teas from potential counterfeits by analyzing their unique heavy metal profiles.
• To leverage X-ray fluorescence (XRF) spectroscopy combined with pattern recognition for tea authentication.

Summary:

• A novel approach was developed utilizing X-ray fluorescence (XRF) spectroscopy to analyze the heavy metal content in tea samples from different regions.
• Principal component analysis (PCA) was employed to reduce the dimensionality of the spectral data, and Mahalanobis distance was used for classification.
• The method successfully classified 120 tea samples from four distinct origins in Zhejiang province, China, with an accuracy rate of 95.8% (4.2% error rate).
• Specific spectral regions (3-13 KeV) and the first four principal components were identified as crucial for accurate regional discrimination.

Impact:

• Provides a reliable and efficient tool for tea industry stakeholders to combat fraud and ensure product authenticity.
• Enhances consumer trust by safeguarding the integrity of famous and origin-guaranteed tea brands.
• Contributes to the scientific understanding of geographical influence on tea composition and develops advanced analytical methodologies for food authentication.