Combating Spice Fraud Using Near-Infrared Spectroscopy

Near-infrared (NIR) spectroscopy is a vibrational spectroscopy technique used to analyze the absorption bands resulting from combination vibrational bands of the molecules within a sample (1). It is often used in the food and beverage industry to verify the authenticity of various food products. According to a study published in Trends in Food Science and Technology, NIR spectroscopy can be used to not only verify spice authenticity, but also detect adulteration and identify its geographical origin (2).

The global spice industry is a lucrative industry. According to a study published in 2020, the global spice market exceeded $20 billion (3). Many spices are expensive because of the labor-intensive processes required for their preparation (3). Spices are produced worldwide, from small plots to large, mechanized farms, and pass through multiple stages in the supply chain, increasing the risk of fraud and contamination. Because of these processes, spices can be adulterated, contaminated, or substituted with cheap or harmful materials (3). These unethical practices not only undermine consumer trust, cause potential health issues, and also threaten the economic interests of genuine producers.

composition with different spices and herbs | Image Credit: © andriigorulko - stock.adobe.com.

Shawky and the team explored this issue in depth by highlighting the potential of NIR spectroscopy as a solution to these issues, thanks to the technique’s rapid, non-destructive, and multi-component analysis capabilities. The researchers explained how NIRS technology operates by measuring the absorption of near-infrared light by various components in a sample (2). This absorption pattern, or spectrum, provides a unique "fingerprint" for each substance, making it an effective tool for identifying and verifying the composition of spices (2). The technique's ability to perform comprehensive analyses quickly and without damaging samples makes it highly suitable for the spice industry (2).

The study acknowledges the current state of NIR spectroscopy applications in spice authentication and explores recent technological advancements. One notable development is the advent of portable NIRS devices, which have the potential to revolutionize the field by enabling on-site, real-time analysis (2). These portable devices enhance the precision and versatility of NIR spectroscopy, making it more accessible and practical for industry professionals (2).

The industry has also benefitted from the integration of machine learning (ML) and artificial intelligence (AI) with NIR spectroscopy. What machine learning and AI are able to do is refine the accuracy of spice authentication, which is useful for distinguishing between genuine and adulterated products more effectively (2).

As the demand for authentic and high-quality spices continues to grow globally, the importance of robust authentication methods continues to be paramount. Shawky's review highlights the crucial role and advancements that NIR spectroscopy has played in the spice industry. The insights gained from this research are valuable not only for researchers and industry professionals, but also for policymakers who aim to regulate and protect the spice market.

By addressing the challenges and limitations of current NIRS applications, the researchers hope to contribute to the ongoing efforts to ensure the authenticity of spices in the global market. As technology continues to advance, the integration of NIRS with other emerging technologies promises to further enhance its effectiveness, safeguarding the interests of consumers and legitimate stakeholders in the spice industry.

References

(1) Bec, K. B.; Grabska, J.; Huck, C. W. Near-Infrared Spectroscopy in Bio-Applications. Molecules 2020, 25 (12), 2948. DOI: 10.3390/molecules25122948

(2) Shawky, E.; Nahar, L.; Nassief, S. M.; et al. Spice Authentication by Near-Infrared Spectroscopy: Current Advances, Limitations, and Future Perspectives. Trends Food Sci. Technol. 2024, 148, 104522. DOI: 10.1016/j.tifs.2024.104522

(3) Ford, P. W.; Berger, T. A.; Jackoway, G. Spice Authentication by Fully Automated Chemical Analysis with Integrated Chemometrics. J. Chromatogr. A. 2022, 1667, 462889. DOI: 10.1016/j.chroma.2022.462889