Physico-chemical characteristics and sensory attributes of coffee beans submitted to two post-harvest processes

Abstract

Post-harvest processes (PHP) interfere with the quality of the coffee beverage. Recently, biochemical phenomena and critical points concerning coffee quality in PHP were identified. The objective was to evaluate the chemical composition and sensory attributes of green beans and roasted coffee beans from natural (CN) and semi-dry (CD) PHP. Samples were processed by coffee growers from a Brazilian coffee-producing region. The physico-chemical variables of green and roasted beans and sensory attributes were grouped in order to apply a multiple factorial analysis. This analysis showed that the description of CN and CD coffees depended on the group of variables employed. Certain aroma and flavor precursors, such as sucrose, proteins and 5-CQA, were associated with the year of production, whereas lipids, phenolic compounds, caffeine and chlorogenic acids, were associated with the PHP. Effects attributed to the occurrence of germination during drying were observed in both processes and had reflexes on the sensorial attributes. The results of the samples prepared by the producers are similar to the results obtained in laboratory experiments by other authors. The same attributes were found in the description of both processes, suggesting that they depend on the content of precursors in the green coffee beans. The formation of the precursors was influenced by factors related to peeling and drying of the green coffee. The control of these favor factors enabled the success of each PHP.