The properties of photon emission arising from a browned product were investigated. The photon intensity of the browned product was proportional to the absorbancy at 420 nm, and was influenced by the amino acid structure. The fluorescence spectrum showed similar compounds in the browned product to be related with this photon emission. Superoxide and hydrogen peroxide contributed highly to this photon emission, and several redox compounds enhanced the photon intensity at appropriate concentrations. Our work suggests that the photon intensity was closely related to the reactive oxygen species (ROS) generated from the browned product, and this effect may be utilized to evaluate the function and quality of browned food.