CASE STUDIES
Industry: Food
Solution: COBRA HyperSpec
Challenge
Herbs are a high-value segment of the food industry and are frequently targeted for fraud. A coordinated EU survey reported that almost 17% of the samples tested showed signs of adulteration. This included the use of fillers, addition of stem or leaf material, or substitution with a visually similar but cheaper herb.
Detecting adulteration is difficult once herbs are dried and ground. Many adulterants are indistinguishable to the eye, and visual inspection alone cannot confirm authenticity. The impact is not only economic, it also affects consumer trust and, in some cases, product safety when unapproved materials enter the supply chain.
The complexity comes from the chemistry of herbs themselves. They contain structural plant matter as well as secondary metabolites such as terpenes, phenolic acids, and chlorophylls. These compounds give each herb a spectral fingerprint, but the differences are subtle and can be masked. Traditional methods have used halogen illumination with chemometric analysis to study authenticity, but halogen sources are unstable over time. Drift in the light source produces inconsistent results, reducing confidence in measurements. Reliable, non-destructive methods are needed to identify these subtle differences and improve the accuracy of authenticity testing.
The Solution: COBRA HyperSpec
ProPhotonix COBRA HyperSpec
A hyperspectral SWIR imaging system illuminated by the COBRA HyperSpec was employed to analyze dried herb samples. Both authentic herbs and adulterated samples were tested. The adulterants chosen were visually similar to authentic herbs, providing a realistic assessment of detection capability.
Spectral signatures were collected across absorption bands associated with chemical bonds, including C–H, O–H, N–H, and C=O. These functional groups are directly linked to the organic compounds present in herbs, making them key markers for authenticity and chemical composition.
Figure 1: Spectral plot illustrating separation between authentic and adulterated herbs
Chemometric classification models were then developed to evaluate the data. These models leveraged the differences in spectral profiles to accurately distinguish between authentic and adulterated herbs. The analysis was designed not only to separate classes but to test robustness across multiple herb types.
Outcome
The hyperspectral analysis produced strong and reliable results:
- Clear separation: Spectral plots showed distinct differences between authentic and adulterated herbs.
- High accuracy: Chemometric classification achieved accuracies of up to 98%, demonstrating the effectiveness of the approach.
- Transferability: The method was effective across multiple herb types, showing it can be applied broadly rather than to a single product.
- Repeatability: Consistent performance across runs highlighted the reliability of the system.
- Non-destructive: Samples remained intact, making this approach suitable for practical food authentication and quality assurance processes.
Figure 2: Classification results demonstrating accuracies of up to 98%
Why COBRA HyperSpec
- Consistent spectral output: Unlike halogen illumination, which drifts over time, COBRA HyperSpec provides stable, repeatable illumination.
- Reliable performance: Ensures accuracy and repeatability in chemometric models.
- Non-destructive: Enables rapid authentication of dried herbs without damaging samples.
Explore further into our offerings encompassing hyperspectral imaging solutions and multispectral imaging solutions. Contact us and receive free professional advice now.
