The photoacoustic (PA) technique allows a spectroscopic analysis of organic opaque samples and its thermal characterization; so this technique gives information about the pigmentation and the roasting modelling parameters, important for industry and commercialization process, when it is applied to green and powdered coffee samples, respectively. A spectrum is particular of each sample; so is possible to identify different characteristics in coffee powder, for example: purity, caffeine content, roasting level, origin conditions, etc. Powdered coffee PA spectroscopic measurements and correlation analysis that allow proposing a discrimination criterion are reported in this work. Also, the thermal diffusivity of green coffee samples was measured by open cell PA technique, in order to study the relation of this parameter with the bean cellular structure, which was looked through an optical microscopy. The results presented will allow a possible method for certifying organic coffee, which is cultivated without chemicals and has greater price in the international market and positive impact on the environment.