Introduction

The agri-food industry constantly faces the challenge of ensuring the safety, quality, and authenticity of its products. In this context, spectroscopy emerges as a crucial scientific tool, widely applied to analyze the composition and quality of foods. The interaction between matter and electromagnetic radiation allows scientists to obtain detailed information about the components and properties of food in a non-invasive and real-time manner.

One of the main advantages of spectroscopy techniques over other technologies is their ability to perform rapid and precise measurements without destroying the sample. This is essential for quality control in mass production, where it is impractical to use methods that require extensive or destructive sample processing. Furthermore, these techniques can be easily adapted for online monitoring, enabling real-time adjustments in production processes to ensure consistent product quality.

The diversity of available spectroscopy techniques also allows for choosing the most suitable method according to the type of sample and required parameter, some of which are described later [1].

Optical Spectroscopy Used in the Food Industry

1. UV-Visible Spectroscopy: Based on the Beer-Lambert law, this technique measures light absorption in the ultraviolet and visible regions. For example, this technique is crucial in the oils industry where it is used to measure fat oxidation, a key indicator of product quality and freshness. Additionally, it is ideal for determining pigments such as carotenoids in agricultural products, which are important for evaluating the antioxidant properties and nutritional value of fruits and vegetables [2].
2. Fluorescence Spectroscopy: Detects light emitted by substances after being excited by a light source. Some of its applications include the detection of microbial contamination. This technique is widely used to analyze the quality of dairy products such as milk and cheese, where natural fluorophores can indicate changes due to fermentation or spoilage. It is also applied in the detection of adulterations in products such as olive oil, by identifying specific phenolic compounds [3].
3. Infrared Spectroscopy (IR): Explores specific molecular vibrations that arise when absorbing infrared light, being effective in identifying functional groups in foods and providing information on freshness and composition. It is applied to determine the composition of processed foods, providing quick information on fat, protein, and moisture content without the need for complex sample preparation [4]. IR spectroscopy, specifically near-IR (NIR), also finds numerous applications in the fruit, vegetable, meat, and wine industries as described in articles published on our blog on these topics.
4. Raman Spectroscopy: Utilizes the Raman effect to provide details on the vibrational changes of molecules, useful in the structural analysis of foods and in evaluating changes due to storage or processing. For example, it is used to determine the molecular structure of complex foods, aiding in the analysis of ingredient distribution and quality within food blends [5]. It is also used to evaluate the structural integrity of foods subjected to freezing and thawing processes, crucial for seafood and processed meats.
5. Nuclear Magnetic Resonance (NMR) Spectroscopy: Harnesses the magnetic properties of atomic nuclei to analyze molecular structure and detect adulterations. It is essential for studying molecular dynamics in liquid foods such as juices and wines, where it can identify and quantify volatile and non-volatile metabolites responsible for aroma and flavor [6]. Additionally, it is used for quality control in beer production, where the metabolite profile can be crucial for the final product.
6. Atomic Emission Spectroscopy: Excites atoms to measure emitted light, determining the presence of heavy metals and other trace elements. It is applied to ensure that foods comply with regulatory limits for trace elements. This technique is used to analyze the presence of potentially toxic elements such as lead and cadmium in cereals and vegetables [7].

Conclusion

The application of spectroscopy techniques in the food industry not only reinforces quality and safety standards but also offers a robust methodology for rapid and non-destructive analysis of foods, essential for innovation and consumer satisfaction in the global market. Additionally, the recent introduction of artificial intelligence-based algorithms that complement the results obtained through the aforementioned techniques represents a significant advancement for these technologies and an improvement in the production processes of agri-food industries.

Bibliography:

1. Mishra, M. (2022). Spectroscopic techniques for the analysis of food quality, chemistry, and function.
2. Zamarreño, C. R., Gracia-Moises, A., Vitoria, I., Imas, J. J., Castaño, L., Avedillo, A., & Matías, I. R. (2022, October). Alfalfa quality detection by means of VIS-NIR optical fiber reflection spectroscopy. In 2022 IEEE Sensors (pp. 1-4). IEEE.
3. Karoui, R., & Blecker, C. (2011). Fluorescence spectroscopy measurement for quality assessment of food systems—a review. Food and Bioprocess technology, 4, 364-386.
4. Wilson, R. H., & Tapp, H. S. (1999). Mid-infrared spectroscopy for food analysis: recent new applications and relevant developments in sample presentation methods. TrAC Trends in Analytical Chemistry, 18(2), 85-93
5. Jin, H., Lu, Q., Chen, X., Ding, H., Gao, H., & Jin, S. (2016). The use of Raman spectroscopy in food processes: A review. Applied Spectroscopy Reviews, 51(1), 12-22.
6. PARlAk, Y., & Güzeler, N. U. R. A. Y. (2016). Nuclear magnetic resonance spectroscopy applications in foods. Curr. Res. Nutr. Food Sci, 4, 161-168.
7. Thirumdas, R., Janve, M., Siliveru, K., & Kothakota, A. (2019). Determination of food quality using atomic emission spectroscopy. In Evaluation Technologies for Food Quality (pp. 175-192). Woodhead Publishing.