Figure 4

Chemical mapping of a large-scale sample measured by the developed Raman plate reader. (a) Photograph of a pork slice under illumination through multiple objective lenses. (b) Representative spectra obtained from the sample for the measurement time of 85 s. (c) Reconstructed chemical map of the sample. Green: fat (Raman intensity at 2890 cm⁻¹), red: Zn-protoporphyrin IX (average intensity of fluorescence peak between 578 and 615 nm; 1496–2530 cm⁻¹).