Enhanced Raman spectroscopic discrimination of the geographical origins of rice samples via transmission spectral collection through packed grains

► Raman spectroscopy was evaluated for geographical discrimination of rice samples. ► Both back-scattering and transmission measurements were compared for the discrimination. ► Transmission measurement accomplished through the rice packing led to the improved discrimination. ► To support the result, compositional inhomogeneity inside a rice grain was confirmed by Raman microscopy.