Relationship between physical changes in the coffee bean due to roasting profiles and the sensory attributes of the coffee beverage

The physical or morphological integrity of the coffee bean during post-harvest processing directly influences the economic value and sensory quality of the coffee beverage. Breakdowns in the outer layers of the beans are characteristics observed for the morphological and economic classification of coffee beans during the commercialization of this product. However, physical changes in the inner layers of the beans that are not seen with the naked eye can also influence the sensory quality of the coffee. Therefore, the objective of this study was to relate changes in the physical structure of coffee beans roasted by four different processes (light, medium, dark, and baked) with the sensory attributes of the beverage. The analyses of the physical characteristics of the coffee beans were carried out by X-ray microtomography and the sensory profile was determined using the Specialty Coffee Association of America protocol. The roasting profile with the highest sensory scores showed higher values for total pore space volume and a negative Euler number. However, the roasting profiles that fluctuated between the highest and lowest of scores of the sensory attributes did not present standardized behavior for the connectivity, Euler number, and total pore space volume. Hence, morphological or physical changes in the coffee beans caused by the different types of roasting correlate with changes in the sensorial profile. Furthermore, the sensory discrimination of these coffee beans among the different roast profiles may be observed by the joint analysis of the flavor and fragrance scores.