Textured vegetable protein (TVP) is a significant alternative to meat, with its primary raw materials being soybeans, peas, rice, and wheat proteins. While advancements in technology have successfully replicated the unique texture of meat in plant-based proteins, research on the aroma profiles of these key raw materials remains limited. The subtle differences in aroma between meat and meat substitutes are yet to be fully addressed. In this study, we employed headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS), a specialized technique for the analysis of volatile aromatic compounds, to examine the volatile profiles of soybean, pea, rice, and wheat proteins. The identified volatile compounds included alcohols, aldehydes, carboxylic acids, ethers, furans, indoles, ketones, phenols, pyrans, and sulfur compounds. Based on prior research, eight compounds (hexanal, nonanal, 2-nonenal, 3-methylbutanal, benzaldehyde, 1-octen-3-ol, 3-octen-2-one, and 2-pentylfuran) were classified as off-flavors. Hexanal, a key marker, was found in the following order: rice showed the highest levels, followed by soybeans, peas, and wheat. Other major volatile components exhibited distinct ratios across the samples. These findings could assist in refining the next generation of TVPs and minimizing aroma heterogeneity.