Vibrational Spectroscopy in Plant-Based Protein Research: Quantification and Structural Analysis

Abstract

Background: Plant-based proteins are gaining importance in food science, biotechnology, and human health as sustainable and nutrient-rich alternatives to animal-derived proteins. The rising demand for plant-based foods, driven by environmental concerns and dietary shifts, has intensified research into plant protein sources. Accurate determination of protein content and structure is essential for ensuring the nutritional quality, optimizing functionality, and maintaining product consistency. Traditional protein analysis methods, while effective, often require extensive sample preparation and time-consuming procedures. Vibrational spectroscopy, including Fourier-transform Infrared (FTIR), Near-Infrared (NIR), and Raman spectroscopy, offers a rapid, non-destructive, and efficient alternative for protein characterization in complex food matrices. Scope and approach: This review explores the application of vibrational spectroscopy in evaluating plant-based protein content and their secondary structure. It outlines the fundamental principles of FTIR, NIR, and Raman spectroscopy, emphasizing their advantages over conventional techniques. Key challenges, such as spectral overlap, water interference, and calibration requirements, are discussed alongside emerging solutions involving chemometric approaches, artificial intelligence, and hybrid analytical techniques. Key findings and conclusions: Vibrational spectroscopy provides precise protein quantification and structural analysis with minimal sample preparation. FTIR and Raman spectroscopy complement each other in protein conformation analysis, while NIR facilitates rapid bulk protein assessment. Advances in computational methods are enhancing spectral interpretation and accuracy. Integrating vibrational spectroscopy with complementary techniques can further improve protein characterization, supporting the development of high-quality, sustainable plant-based protein sources for food and biotechnology applications.