Key Points
- A review by researchers at the Izmir Institute of Technology highlights how vibrational spectroscopy techniques are being used to non-destructively analyze the composition and structure of plant-based proteins.
- While these spectroscopic methods allow for real-time, high-throughput analysis and hold promise for in-line quality control in food production, challenges such as spectral overlap, water interference, and the need for strong calibration models remain significant hurdles.
- The integration of chemometrics, AI-driven models, and complementary technologies like mass spectrometry and hyperspectral imaging is helping to overcome limitations, paving the way for more accurate, automated, and holistic food quality assessments.
Plant-based proteins are surging in popularity among consumers. With increased attention on these products, plant-based meat alternatives are being subject to more evaluations that assess their nutritional quality using analytical techniques. In a recent review article published in Trends in Food Science & Technology, a team of researchers from the Izmir Institute of Technology in Turkey, discussed the role of vibrational spectroscopy in plant protein characterization (1).
What are vibrational spectroscopy techniques?
Vibrational spectroscopy techniques include Fourier transform infrared (FT-IR), near-infrared (NIR), and Raman spectroscopy. These techniques are used in food analysis to analyze the chemical components of the ingredients in food products, including plant-based proteins (2).
What are plant-based proteins?
Plant-based proteins are food products known for their environmental benefits and rich nutrient profiles (1). These proteins, derived from sources such as soybeans, lentils, quinoa, sunflower seeds, and even byproducts like bran and defatted meals, are increasingly used in meat analogs, dairy substitutes, and functional foods (1).
What is the current issue with analyzing plant-based formulations?
Plant-based formulations become more complex and widespread. As a result, the traditional laboratory techniques that were used to analyze these food products are no longer sufficient. Although developments in instrumentation and hardware have aided analysis, researchers are still encountering challenges with current methods.
For example, protein analysis has relied on methods such as Kjeldahl and Dumas, which, although effective, are labor-intensive and require extensive sample preparation (1). Researchers are exploring how vibrational spectroscopy can help because these techniques are non-destructive and efficient. This review article explains how FT-IR, NIR, and Raman spectroscopy are being used to generate reports into protein composition and structure (1).
How are vibrational spectroscopy techniques contributing to protein analysis?
The research team shows how each vibrational spectroscopic technique is helping to improve protein analysis. For example, FT-IR and Raman spectroscopy have been used to study protein secondary structures through the detection of specific molecular vibrations (1). Both techniques are highly complementary, with FT-IR spectroscopy often used for polar functional groups and Raman spectroscopy for detecting non-polar groups (1). Meanwhile, NIR spectroscopy facilitates rapid, high-throughput quantification of protein content in bulk food materials, making it ideal for routine industrial use (1).
What are the challenges of using vibrational spectroscopy?
Using NIR, Raman, and FT-IR spectroscopy carries several benefits as highlighted above, but there are also several important challenges. These challenges include spectral overlap caused by the complexity of food matrices, water interference that can obscure key signals, and the need for robust calibration models to ensure accuracy across different samples and conditions (1).
One solution researchers have come up with is using chemometric tools and artificial intelligence (AI). AI-driven models can detect subtle patterns in complex spectra, automate feature selection, and generate predictive models with improved generalizability (1). The integration of vibrational spectroscopy with complementary analytical techniques, including mass spectrometry (MS) and hyperspectral imaging (HSI), is also opening new frontiers in comprehensive food characterization (1).
This solution is spurring the move toward more automated and data-driven quality control systems. As a result, vibrational spectroscopy is poised to continue to play a central role in monitoring the authenticity, nutritional value, and functional properties of plant-based proteins (1).
Furthermore, the real-time capabilities of vibrational spectroscopy offer significant advantages for in-line monitoring in manufacturing settings. This could enable immediate feedback during food processing, ensuring product consistency and reducing waste (1).
What are the future directions of this work?
The research team advocated for future research focusing on expanding the applicability of these spectroscopic methods to more complex and heterogeneous food systems. They also highlighted the potential of integrating data fusion strategies, which combine data from multiple sources to produce more accurate and holistic assessments of food quality (1).
Plant-based diets continue to grow in popularity, with sales growing 6.6% as of 2022 (3). As the global transition toward plant-based diets continues, ensuring the quality and integrity of alternative proteins is critical (1). This study shows that vibrational spectroscopic techniques will continue to be used to improve food analytics and production now and in the future.
References
- Cavdaroglu, E.; Cavdaroglu, C.; Ozen, B. Vibrational Spectroscopy in Plant-based Protein Research: Quantification and Structural Analysis. Trends Food Sci. Technol. 2025, 161, 105058. DOI: 10.1016/j.tifs.2025.105058
- Cozzolino, D. An Overview of the Successful Application of Vibrational Spectroscopy Techniques to Quantify Nutraceuticals in Fruits and Plants. Foods 2022, 11 (3), 315. DOI: 10.3390/foods11030315
- Plant Based Food Association, 2022 U.S. Retail Sales Data for the Plant-based Foods Industry. Plant Based Food Association. Available at: https://plantbasedfoods.org/2022-retail-sales-data-plant-based-food (accessed 2025-07-07).
