Rice (Oryza sativa) is staple food for more than half of the world population. This cereal contributes a considerable amount of calories to the consumer. Agrotoxics and synthetic fertilizers in agricultural practices have generated environmental damage and the pollution of fruits, which puts consumer health at risk. On the other hand, organic agricultural production requires certification, which frequently is a complicated and expensive process of inspection. For this reason, it is pertinent to look for a scientific discrimination criterion that allows for the certification procedure to be done in an efficient and economical way. In this paper, a photoacoustic spectroscopy study for husk and white grain rice samples of Combeima variety is shown. The samples were taken from crops of rice that were cultivated with organic and conventional techniques. Themophysical parameters of the same kind of samples were measured with the same technique, but in frequency - resolved configuration. Finally, rice grain cell morphology was studied by optical microscopy. The results show important differences among the samples for being used in a certification process.