Related Experiment Video
Updated: Jul 20, 2026
10:25
Construction of Models for Nondestructive Prediction of Ingredient Contents in Blueberries by Near-infrared Spectroscopy Based on HPLC Measurements
Published on: June 28, 2016
Bilberry adulteration using the food dye amaranth
Kerry G Penman1, Clynton W Halstead, Anita Matthias
1MediHerb Research Laboratories, 3/85 Brandl Street, Eight Mile Plains, Brisbane, Queensland 4113, Australia.
Journal of Agricultural and Food Chemistry
|September 14, 2006
Summary
Bilberry (Vaccinium myrtillus) supplements are often adulterated with synthetic dyes like amaranth. Standard spectrophotometric assays fail to detect this, highlighting the need for advanced methods like HPLC for accurate anthocyanin content analysis.
Area of Science:
- Phytochemistry
- Analytical Chemistry
- Herbal Medicine Analysis
Background:
- Vaccinium myrtillus (bilberry) fruit is a popular herbal product.
- Anthocyanin content is typically measured using single-wavelength spectrophotometry.
- Concerns exist regarding the accuracy of standard assays for complex herbal matrices.
Purpose of the Study:
- To evaluate the accuracy of spectrophotometric assays for bilberry anthocyanins.
- To identify potential adulterants in commercial bilberry extracts.
- To compare analytical methods for detecting adulteration.
Main Methods:
- Analysis of two bilberry extracts using single-wavelength spectrophotometry.
- High-performance liquid chromatography (HPLC) for detailed compound profiling.
- Mass spectrometry (MS) and nuclear magnetic resonance (NMR) for structural identification of adulterants.
Main Results:
- Spectrophotometry indicated 25% anthocyanin content in both extracts, matching manufacturer claims.
- HPLC revealed one extract contained only 9% anthocyanins, suggesting adulteration.
- The adulterant was identified as amaranth, a synthetic naphthylazo dye.
Conclusions:
- Single-wavelength spectrophotometry is insufficient for accurately quantifying anthocyanins in potentially adulterated bilberry extracts.
- Amaranth adulteration in bilberry products can be misidentified by standard assays.
- Advanced analytical techniques, such as HPLC with photodiode array detection, are essential for detecting deliberate adulteration in herbal products.
