This research provides a large database of spectroscopic measurements from β-D-glucans extracted from various mushrooms and cereal grains. The data includes detailed chemical fingerprints obtained through two analytical techniques (NMR and infrared spectroscopy) that can help researchers understand the structure and properties of these beneficial compounds. The dataset is freely available for other scientists to analyze and use for developing new methods or understanding how different mushroom and cereal sources vary in their chemical composition.